JP6096567B2 - Thermal desorption analysis method, thermal desorption analyzer, and program - Google Patents

Description

  The present invention relates to a temperature-programmed desorption analysis method, a temperature-programmed desorption analysis apparatus, and a program for analyzing a chemical species derived from a component contained in a sample using a solid material as a sample.

  As a method for analyzing a gas component or a component desorbed as a gas at a high temperature among chemical species components present in the solid sample, there is a temperature programmed desorption analysis method. An apparatus for performing temperature-programmed desorption analysis is called a temperature-programmed desorption analyzer (Non-Patent Documents 1 and 2).

  The temperature-programmed desorption analysis method was originally mainly used as an analysis method for measuring a contaminated gas component on a semiconductor surface or inside a semiconductor or an adsorbed component of a semiconductor material. However, in recent years, it has also been used as an analytical method for measuring the amount of intrusion of gas components such as hydrogen that impair the mechanical properties of steel.

  Thermal desorption analysis usually involves increasing the temperature of a solid sample at a constant rate of temperature increase in a vacuum, and desorbing the component released from the solid sample at each temperature and releasing it into the vacuum, such as electron impact. Ionized by ion method, ionized components are separated by mass / charge ratio with a mass spectrometer, led to a detector, and the amount of ionized gas components is measured as a current value, or ionized gas components Each one is detected as a voltage pulse, and this voltage pulse is amplified and counted. That is, the signal obtained by the temperature programmed desorption analysis is a current or counted pulse of an ion having a certain mass / charge ratio derived from a certain component. The signal strength is the amount of current measured during a certain time or the number of pulses counted. A graph in which the horizontal axis represents temperature and the vertical axis represents signal intensity is referred to as a temperature programmed desorption curve.

  From the temperature programmed desorption spectrum in which a component present in a solid sample is desorbed as a gas, knowledge about the energy for desorbing the component as a gas can be obtained. Since the existence state is closely related, the existence state of the component present in the solid sample can be known by obtaining the temperature-programmed desorption spectrum. Energy for desorbing a component present in a solid sample as a gas is generally called activation energy. For example, if a temperature-programmed desorption spectrum can be measured and analyzed for a component in a solid state that is strongly bound to a trap site in a solid, the activation energy is higher than that in a weakly bound state. Is shown.

  In a temperature-programmed desorption analysis method using a known technique, if a temperature-programmed desorption curve in which a component present in a solid sample is desorbed as a gas is measured and the temperature-programmed desorption curve can be analyzed, Knowledge should be obtained and the presence state of the component present in the solid sample should be known, but it is not easy to analyze it.

  If the amount of the component present in the solid sample at time t = 0 is 1, and the amount of the component desorbed as a gas by time t is x, the reaction rate is given by the following equation in chemical reaction theory. However, t = 0, x = 0, and x = 1 after a sufficient time.

  Here, g (x) is a function of x determined by the type of chemical reaction, and k is a rate constant. In many elimination reactions, the Arrhenius law expressed by the following equation holds.

Here, A is a constant called a frequency factor, R is a gas constant, T is the temperature of the sample, and E _a is the activation energy.
Since the signal intensity I (t), which is the vertical axis of the temperature-programmed desorption curve, is proportional to the amount of chemical species desorbed from the sample at regular time intervals, the following is obtained when the time interval is sufficiently small. As shown in the equation, it is proportional to dx / dt.

  G (x) in Formula 1 is represented by the following formula in the n-th order reaction.

  The desorption of hydrogen from steel is almost always described as n = 1 (Non-Patent Document 6). In order to analyze the elimination reaction and obtain the activation energy, it is most fundamental to express dx / dt or the integral x of dx / dt, which is proportional to the signal intensity I (t), as a function of time t. From Equation 1, Equation 2, and Equation 4, Equation 5 is obtained when n = 1.

  In ordinary temperature programmed desorption analysis, the temperature of the solid sample is increased at a constant rate of temperature increase, so the following equation is established.

Here, T ₀ in Equation 6 is the temperature of the sample at t = 0, and β is the rate of temperature increase. As is clear from Expression 2 and Expression 6 that Expression 7 holds, the speed constant k is not constant with respect to time.

  When the temperature of the solid sample is increased at a constant rate of temperature increase, the following equation is obtained.

  However, the right side of Equation 8 when the temperature of the solid sample is raised at a constant rate of temperature rise cannot be expressed by an elementary function. This function is represented by a function called Doyle's p function (Non-Patent Documents 3 and 4).

  In the actual analysis so far, the approximate expression of the p function is used instead of the Doyle p function itself, and the temperature rise rate β is utilized by utilizing the fact that the left side of Expression 8 is constant at the upper limit x of a certain integration range. The measurement is performed several times, and the activation energy is obtained by obtaining several combinations of the values of t and β in which the values of Equation 8 are equal (Non-patent Document 5).

  However, different approximation formulas may be used depending on the approximation method, and the analysis method is not uniform. As long as it is an approximation, the conditions under which the approximation is established are limited, and the accuracy is also limited.

  In addition, for example, when three experiments are performed under the condition where the heating rate β is changed, three samples (hereinafter referred to as the same sample) in which the components present in the solid sample can be regarded as the same existence state are prepared. There must be. In three experiments, a sample must be put into the apparatus every time, and the apparatus must be in a high vacuum state that allows measurement. Of the three times, the measurement time is often 3 hours or more under the condition of the lowest rate of temperature increase. In addition, during each experiment, it is necessary to lower the temperature of the apparatus to about room temperature, but it usually takes about one hour to lower the temperature of the apparatus. That is, it takes time to perform all measurements, and it may take a day.

  In addition, the condition that three samples that can be regarded as the same are prepared is possible if the sample is prepared by artificial control, but even if the sample is obtained from the natural world or is an artificial object, If it is taken out from the environment after exposure, there is only one sample, and it is impossible to satisfy the above conditions.

Shukuni Enomoto, “Application of temperature programmed desorption analysis to silicon surface evaluation”, Surface Technology, Vol. 46, no. 3, p. 249-252, 1995 Michihiko Nagumo, “Basics of Hydrogen Embrittlement, Hydrogen Behavior and Embrittlement Mechanism,” Uchida Otsukuru, p. 55-67, 2008 C.D.Doyle, “Kinetic Analysis of Thermogravimetric Data”, J.Appl.Polym.Sci., Vol.5, No.15, p.285-292, 1961 C.D.Doyle, “Series Approximations to the Equation of Thermogravimetric Data”, Nature, Vol.207, N0.4994, p.290, 1965 Takeo Ozawa, “Non-constant temperature kinetics (1) In the case of a single elementary process”, Thermal measurement, 31 (3), p.125-132, 2004 W.Y.Choo, “Thermal Analysis of Trapped Hydrogen in Pure Iron”, Metall.Trans.A, Vol.13A, p.135-140, 1982

  As described above, in the temperature-programmed desorption analysis method using a known technique, it is not easy to analyze the temperature-programmed desorption curve for obtaining the activation energy, and the accuracy is limited because an approximate expression is used. Also, measurement and analysis under conditions in which the temperature rising rate β is changed in some ways are impossible in some cases.

  The present invention has been made in order to solve the above-described problems. A temperature-programmed desorption analysis method, a temperature-programmed desorption analyzer, and a thermal desorption analyzer that can easily determine the activation energy value of a component present in a solid sample. The purpose is to provide a program.

The temperature-programmed desorption analysis method of the present invention is a temperature that controls the temperature of a solid sample according to a temperature program that heats the solid sample and uses the temperature as a function that increases in inverse proportion to the linear expression of time from the temperature at time 0. A control step, a detection step of detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals, a maximum value of the signal intensity, and a first time at which the signal intensity exhibits a maximum value; A second extraction step of extracting a second time indicating a signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1, and a second time of 0. A time conversion step in which the first time is represented by the conversion time as the conversion time, or the second time is represented by the conversion time as the conversion time as the conversion time. And said strange Activation when the component desorbs from the solid sample from the first time represented by time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number And an activation energy deriving step for obtaining energy.
Further, in one configuration example of the temperature programmed desorption analysis method of the present invention, the second time is the first time among the times indicating the signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1. It is a time earlier than the time, and the time conversion step represents the first time by the conversion time, where the second time is 0, and the activation energy deriving step is the conversion time The activation energy when the component desorbs from the solid sample is obtained from the first time represented by time and the predetermined positive number.
Further, in one configuration example of the temperature programmed desorption analysis method of the present invention, the second time is the first time among the times indicating the signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1. The time conversion step represents the second time as the conversion time, with the time when the first time is 0 as the conversion time, and the activation energy deriving step includes the conversion time The activation energy when the component is desorbed from the solid sample is obtained from the second time expressed in time and the predetermined positive number.
Further , the predetermined positive number may be set to 0.5.

The temperature-programmed desorption analyzer of the present invention controls the temperature of the solid sample according to a temperature program that heats the solid sample and sets the temperature to a function that increases in inverse proportion to the linear expression of time from the temperature at time 0. A temperature control means for detecting, a detection means for detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals, a maximum value of the signal intensity and a first value at which the signal intensity shows a maximum value. First extraction means for extracting time, second extraction means for extracting second time indicating signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1, and the second time. The time set to 0 is the conversion time, and the conversion time represents the first time, or the time the first time is set to 0 is the conversion time, and the conversion time represents the second time. The conversion means and the conversion time. Activation for obtaining activation energy when the component is desorbed from the solid sample from the first time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number And an energy deriving unit.

The temperature-programmed desorption analysis program of the present invention controls the temperature of the solid sample according to a temperature program that heats the solid sample and uses the temperature as a function that increases in inverse proportion to the linear expression of time from the temperature at time 0. A temperature control step, a detection step of detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals, a maximum value of the signal intensity, and a first value indicating that the signal intensity is a maximum value. A first extraction step for extracting a time, a second extraction step for extracting a second time indicating a signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1, and the second time. The time set to 0 is the conversion time, and the conversion time represents the first time, or the time the first time is set to 0 is the conversion time, and the conversion time represents the second time. Conversion step And the component desorbs from the solid sample from the first time represented by the conversion time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number. An activation energy deriving step for obtaining activation energy at the time, and causing the computer to execute these steps.

  According to the present invention, while heating the solid sample, the temperature of the solid sample is controlled according to a temperature program whose temperature is a function of time, and the signal intensity proportional to the amount of components desorbed from the solid sample is set at regular intervals. In a temperature-programmed desorption analyzer that detects and records, the signal intensity can be expressed as an elementary function of time that can be analyzed, and the time axis can be converted so that the analysis is simple. As a result, in the present invention, the activation energy value of the component present in the solid sample can be determined directly and simply, and the presence state of the component present in the solid sample can be known.

It is a figure which shows the example of the thermal desorption curve used with the thermal desorption analysis method which concerns on the 1st Embodiment of this invention. It is a block diagram which shows the structure of the temperature-programmed desorption analyzer which concerns on the 1st Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the computer of the thermal desorption analyzer which concerns on the 1st Embodiment of this invention. It is a figure which shows the example of the thermal desorption curve used with the thermal desorption analysis method which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows an example of operation | movement of the computer of the thermal desorption analyzer which concerns on the 2nd Embodiment of this invention. It is a figure which shows the example of the temperature-programmed desorption curve by the conventional temperature-programmed desorption analysis method.

[Principle of the Invention]
In the present invention, the temperature of a sample is controlled according to a temperature program in which the temperature is a function of time, and a temperature desorption analysis that measures and records the signal intensity proportional to the amount of chemical species desorbed from the sample at regular intervals In the method, the plot is performed with the signal intensity as the vertical axis and the conversion time obtained by translating the actual time by a certain constant as the horizontal axis. Thereby, in this invention, the activation energy about a component with a certain existing state can be calculated | required simply, without performing operations, such as an approximation.

  The principle of the present invention will be described below. In describing the present invention, it is convenient to introduce a concept called generalized time. The generalized time θ is defined by the following equation.

  The present invention controls the temperature of a sample in accordance with a temperature program whose temperature is a function of time, and measures and records the signal intensity proportional to the amount of chemical species desorbed from the sample at regular intervals. In this method, a temperature-programmed desorption analysis method is provided in which the vertical axis represents the signal intensity and the horizontal axis represents the conversion time obtained by translating the actual time by a certain constant. When the reaction amount of x at t = 0 is a, Equation 5 in the present invention is converted as follows.

  If the product of the frequency factor A and the generalized time θ is used as a constant multiple of the generalized time θ, the value of this product becomes the value of Equation 10.

  Integrate to obtain Equations 12 and 13.

  Here, the temperature T, which is a function of the time t in the present invention, is a function that is inversely proportional to the linear expression of the time t as shown in the following formula.

  At this time, Expression 15 is obtained from Expression 2.

Here, k ₀ is expressed by the following equation.

  At this time, the right side of Expression 10 is expressed by Expression 17, and Aθ can be expressed by an elementary function.

  Here, when the dimensionless number γ shown in Expression 18 is further introduced, Expression 17 becomes as shown in Expression 19.

  From Expression 13, Expression 20 and Expression 21 are established.

  When the value of Equation 21 is 0, that is,

  That is,

When t _p , Equation 20 has a local maximum and the local maximum

  When standardizing Equation 20 so that the maximum value is 1,

It becomes.
In the first embodiment to be described later of the present invention, for example, the values of generalized time θ at which Equation 25 becomes 0.5 are sequentially set as θ ₁ and θ ₂ , and the times are set as t ₁ and t ₂ . The start time of the time in Expression 15 can be determined as an arbitrary time in the experiment time, not the actual start time in the experiment. Therefore, at the start time, the time t = 0 when x = a is set again by shifting the time axis so as to coincide with t _1, and the temperature at t ₁ is T ₀ . At this time, the generalization time θ ₁ = 0. From Equation 25,

It becomes. There are about 4.31 and about 0.373 as the values of the dimensionless number γ obtained from this equation. However, since γ> 1 is necessary for the value of Equation 23 to be positive, The value is about 4.31. At this time, k ₀ is obtained from Equation 23 using the time t _p obtained in the experiment. Further, the activation energy E _a is obtained from Equation 18.

In the second embodiment to be described later of the present invention, for example, the values of the generalized time θ at which Equation 25 becomes 1 and 0.5 are sequentially set to θ _p and θ ₂ (where θ _p <θ ₂ ), _Let time be t _p , t ₂ . The start time of the time in Expression 15 can be determined as an arbitrary time in the experiment time, not the actual start time in the experiment. Therefore, at the start time, the time t = 0 when x = a is set again by shifting the time axis so as to coincide with t _p, and the temperature at t _p is set to T ₀ . At this time, the generalized time θ _p = 0. Further, from Expression 22, the dimensionless number γ is 1. From Equation 25,

It becomes. By solving this equation 27, a value of about 1.678 is obtained as the value of Aθ ₂ . From Equation 19,

From Equation 28, k ₀ is obtained using the time t ₂ obtained in the experiment. Further, the activation energy E _a is obtained from Equation 18.

[First Embodiment]
Next, embodiments of the present invention will be described with reference to the drawings.

  FIG. 6 shows an example of a temperature programmed desorption curve according to the conventional method.

In the temperature-programmed desorption curve obtained in the experiment, the vertical axis represents signal intensity I (t), the horizontal axis represents time t, and the relationship between temperature T and time t is given by Equation 6. At this time, neither the relationship between the signal intensity I (t) and the time t nor the relationship between the signal intensity I (t) and the temperature T can be expressed by an elementary function. it is difficult to obtain the activation energy E _a and. In the conventional method, the heating rate β in equation 6, the experiments with different heating rate β performed at least three times, the time t _p the signal intensity becomes maximum in FIG. 6, for different heating rate β Obtain the value of t _p , perform plotting, and obtain the activation energy E _a .

  FIG. 1 shows an example of a temperature programmed desorption curve used in this embodiment.

The relationship between temperature T and time t is given by equation 15. The signal intensity I (t) on the vertical axis and the time t on the horizontal axis are defined in the following procedure. First, in the temperature programmed desorption curve obtained in the same manner as in FIG. 6, the signal intensity at which the signal intensity becomes maximum is Imax, and the signal intensity obtained by multiplying Imax by a positive constant smaller than ₁ is I1. At this time, the positive constant smaller than 1 is, for example, 0.5. As the starting point of time t, an earlier time is defined as time t = 0 among two actual times when the signal intensity is I ₁ . The time after the parallel movement as described above with respect to the actual time on the horizontal axis is again defined as time t. At the same time, the signal intensity on the vertical axis at the defined time t is defined as I (t).

  FIG. 2 shows a configuration example of the temperature programmed desorption analyzer of the present embodiment. The temperature-programmed desorption analyzer includes a vacuum chamber 301 that contains a sample 302, an infrared lamp 303, a heat conduction rod 304 that transfers heat from the infrared lamp 303 to the sample 302, and a thermocouple that measures the temperature of the heat conduction rod 304. 305, a thermocouple monitor 306 that outputs a temperature value measured by the thermocouple 305, a temperature controller 307 that controls the temperature of the sample 302 based on the temperature measurement result by the thermocouple 305, and desorption from the sample 302 An ionization chamber 308 for ionizing the gas component, a mass spectrometer 309 for fractionating the ionized gas component for each mass / charge ratio, and measuring the amount of the ionized gas component as a current value, or an ionized gas component A detector 310 that counts each one as a voltage pulse, a display device 312 for displaying data, and the sample 30 It includes a computer 313 for calculating the activation energy of the desorbed components, and an input device 314 for measuring person gives an instruction to the computer 313 from. The infrared lamp 303, the heat conducting rod 304, the thermocouple 305, the thermocouple monitor 306, and the temperature controller 307 constitute temperature control means, and the ionization chamber 308, the mass spectrometer 309, and the detector 310 constitute detection means. doing. The computer 313 constitutes first extraction means, second extraction means, time conversion means, and activation energy derivation means.

  The example shown in FIG. 2 is based on infrared lamp heating, and a solid sample 302 placed in a vacuum chamber 301 is placed on a heat conducting rod 304 directly connected to an infrared lamp 303. The temperature of the sample 302 is measured by a thermocouple 305 placed in the immediate vicinity of the sample 302, and a temperature indication value based on the measurement result is output from the thermocouple monitor 306. When there is a difference between the temperature indication value obtained from the thermocouple monitor 306 and the temperature of the sample 302, the temperature indicated by a thermocouple (not shown) directly attached to the sample 302 in advance and the thermocouple monitor 306 What is necessary is just to calculate | require and calibrate the difference with the indication value of temperature. Here, the temperature of the sample 302 is assumed to be equal to the temperature indication value in the thermocouple monitor 306.

  The temperature controller 307 reads the temperature indication value from the thermocouple monitor 306 so that the temperature of the sample 302 becomes the specified value at the specified time according to the setting before measurement by the measurer, Controls the current value to flow. The method of controlling the temperature of the sample 302 at the next time to a desired set temperature by feeding back the temperature indication value on the thermocouple monitor 306 at a certain time including the present time is proportional control (P control), integration. There are control (I control), differential control (D control), and PID control integrated therewith, but usually PID control that is most easily controlled among these is adopted. Commercially available temperature controllers usually support PID control.

  A part of the gas component desorbed from the sample 302 and released into the vacuum at every certain time is ionized by an ion method such as electron bombardment in the ionization chamber 308, and the ionized gas component is mass / The charge is sorted for each charge ratio and guided to the detector 310. The detector 310 measures the amount of ionized gas component as a current value, or detects each ionized gas component as a voltage pulse, and amplifies and counts the voltage pulse. 311 shown in FIG. 2 is the current or counted pulse of ions having a certain mass / charge ratio derived from a certain gas component, the time being plotted on the horizontal axis, and the signal intensity plotted on the vertical axis. This is an example of a temperature-programmed desorption spectrum to be analyzed. The temperature-programmed desorption spectrum can be displayed on the display device 312 and is recorded in a recording device (not shown) inside the computer 313 or, if necessary, a recording medium (not shown) using a magnetic material or a semiconductor memory. For example).

  Data of the signal intensity I (t) detected by the detector 310 is stored in the data storage unit 3130 of the calculator 313. Needless to say, the data of the signal intensity I (t) is data stored in association with the time.

  After the measurement is finished, the calculation unit 3131 of the calculator 313 extracts the maximum value of the signal strength and the first time when the signal strength shows the maximum value, and multiplies the maximum value by a certain positive number (predetermined positive number). A second time earlier than the first time is extracted from the time indicating the signal strength, the time when the second time is 0 is defined as the conversion time, and the first time is expressed as the first conversion time, The activation energy is obtained from the first conversion time and a certain positive number, and the calculation result of the calculation unit 3131 is stored in the data storage unit 3130.

  In the extraction of the maximum value of the signal strength, the first time, and the second time, if there is a sufficient number of data points, the value closest to the extraction condition is extracted even if it does not strictly match the extraction condition. Also good. If there are a plurality of adjacent data points that match the extraction conditions, the average value may be extracted. Regardless of whether the number of data points is sufficient, a value that matches the extraction conditions on a curve obtained by applying a smoothing process to a discrete data group with the signal strength on the vertical axis and the time on the horizontal axis. It may be extracted.

  A certain positive number may be stored in advance in a recording device inside the computer 313, or may be designated via an input device of the computer 313 during the calculation.

  The calculation unit 3131 may display a graph as shown in FIG. 1 on the display device 312 based on its calculation result. However, in the present invention, drawing the graph as shown in FIG. 1 is not an essential component.

FIG. 3 is a flowchart showing an example of the operation of the computer 313 of the temperature programmed desorption analyzer according to this embodiment. In this flowchart, first, when measurement is completed, data processing is started (step S11), and the relationship between the signal strength and time t is obtained (step S12). Next, determine the maximum value of the signal strength, the time t _p which gives the maximum value for the reaction of interest (step S13). Then, in the relationship between the signal intensity and time t, the time earlier than t _p among the times at which the local maximum value is 0.5 times is defined as t ₁ (step S14). Further, at the conversion time, t _p = t _p −t ₁ (step S15), k ₀ is obtained from the dimensionless number γ = 4.31 and time t _p (step S16), and the activation energy E _a is further obtained (step S16). Step S17).

In the example of the flowchart of FIG. 3, a certain positive number is 0.5. The dimensionless number γ at this time is calculated in advance, and γ = 4.31. The value of the dimensionless number γ is obtained in advance by calculation if a certain positive number is defined. For measurements with high background, a positive value is desirably 0.5 or more, but a value close to 1.0 is not desirable because it is too close to t _p .

[Second Embodiment]
Next, a second embodiment of the present invention will be described. FIG. 4 shows an example of a temperature programmed desorption curve used in this embodiment.

The relationship between temperature T and time t is given by equation 14. The signal intensity I (t) on the vertical axis and the time t on the horizontal axis are defined in the following procedure. First, in the Atsushi Nobori curve obtained in the same manner as FIG. 6, the signal intensity obtained by multiplying a signal strength signal strength is maximum Imax, 1 is smaller than a positive constant to Imax and I _2. At this time, the positive constant smaller than 1 is, for example, 0.5. The starting point of time t is defined as the time t = 0 when the signal intensity becomes maximum. The actual time on the horizontal axis is defined again as the conversion time t after the parallel movement as described above. At the same time, the signal intensity on the vertical axis at the defined conversion time t is defined as I (t).

Also in the present embodiment, the configuration of the temperature-programmed desorption analyzer is the same as that of the first embodiment, and therefore will be described using the reference numerals in FIG.
After the measurement described in the first embodiment is completed, the calculation unit 3131 of the calculator 313 extracts the maximum value of the signal strength and the first time when the signal strength shows the maximum value, and the maximum value is smaller than 1. Of the time indicating the signal intensity multiplied by a positive number (predetermined positive number), a second time later than the first time is extracted, and a time obtained by subtracting the first time from the second time is defined as a conversion time. The second time is expressed as the conversion time, the activation energy is obtained from the second time expressed by the conversion time and a certain positive number, and the calculation result of the calculation unit 3131 is stored in the data storage unit 3130. The

  In the extraction of the maximum value of the signal strength, the first time, and the second time, if there is a sufficient number of data points, the value closest to the extraction condition is extracted even if it does not strictly match the extraction condition. Also good. If there are a plurality of adjacent data points that match the extraction conditions, the average value may be extracted. Regardless of whether the number of data points is sufficient, a value that matches the extraction conditions on a curve obtained by applying a smoothing process to a discrete data group with the signal strength on the vertical axis and the time on the horizontal axis. It may be extracted.

  A certain positive number may be stored in advance in a recording device inside the computer 313, or may be designated via an input device of the computer 313 during the calculation.

  The computing unit 3131 may display a graph as shown in FIG. 4 on the display device 312 based on its calculation result. However, in the present invention, drawing the graph as shown in FIG. 4 is not an essential configuration requirement.

FIG. 5 is a flowchart showing an example of the operation of the computer 313 of the temperature programmed desorption analyzer according to this embodiment. In this flowchart, first, when measurement is completed, data processing is started (step S21), and the relationship between the signal intensity and time t is obtained (step S22). Next, determine the maximum value of the signal strength, the time t _p which gives the maximum value for the reaction of interest (step S23). Then, the relationship between the signal intensity and the time t, of the time at the point of 0.5 times the maximum value, the slower time than t _p and t ₂ (step S24). Further, t ₂ = t ₂ −t _p is set in the conversion time (step S25), k ₀ is obtained from the dimensionless number γ = 1 and time t ₂ (step S26), and the activation energy E _a is further obtained (step S27). ).

In the example of the flowchart of FIG. 5, a certain positive number is 0.5. The dimensionless number γ at this time is given in advance and γ = 1. The value of Aθ ₂ determined by a certain positive number may be stored in advance in a recording device inside the computer 313 or may be designated via the input device of the computer 313 during the calculation. For measurements with high background, a positive value is desirably 0.5 or more, but a value close to 1.0 is not desirable because it is too close to t _p .

  The present invention is not limited to the embodiment described above, and can be applied to thermal analysis methods and thermal analysis devices other than temperature-programmed desorption analysis methods and temperature-programmed desorption analysis devices in vacuum. As is possible, it is obvious that many variations are possible within the technical idea of the present invention by those having ordinary skill in the art.

  The computer 313 of the first and second embodiments can be realized by a computer having a CPU, a storage device, and an interface, and a program that controls these hardware resources. In such a computer, the temperature-programmed desorption analysis program for realizing the temperature-programmed desorption analysis method of the present invention is provided in a state of being recorded on a recording medium such as a flexible disk, CD-ROM, DVD-ROM, or memory card. Is done. The CPU writes the program read from the recording medium into the storage device, and executes the processes described in the first and second embodiments according to this program. It is also possible to provide a temperature programmed desorption analysis program through a network.

  The present invention can be applied to a temperature programmed desorption analysis method for analyzing chemical species derived from components contained in a solid sample.

  DESCRIPTION OF SYMBOLS 301 ... Vacuum chamber, 302 ... Sample, 303 ... Infrared lamp, 304 ... Thermal conducting rod, 305 ... Thermocouple, 306 ... Thermocouple monitor, 307 ... Temperature controller, 308 ... Ionization chamber, 309 ... Mass spectrometer, 310 ... Detection 311 ... Display device, 313 ... Computer, 314 ... Input device, 3130 ... Data storage unit, 3131 ... Calculation unit.

Claims (9)

A temperature control step of controlling the temperature of the solid sample in accordance with a temperature program that heats the solid sample and functions as a function of increasing the temperature from the temperature at time 0 in inverse proportion to the linear expression of time
A detection step of detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals;
A first extraction step of extracting a maximum value of the signal intensity and a first time at which the signal intensity shows a maximum value;
A second extraction step of extracting a second time indicating a signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1;
The time at which the second time is 0 is defined as the conversion time, and the first time is represented by the conversion time, or the time at which the first time is 0 is defined as the conversion time, and the conversion time is the first time. A time conversion step representing the time of 2;
When the component desorbs from the solid sample from the first time represented by the conversion time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number. An activation energy deriving step for obtaining activation energy; The temperature-programmed desorption analysis method according to claim 1,
The second time is a time earlier than the first time among the times indicating signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1,
The time conversion step represents the first time by the conversion time, where the time when the second time is 0 is defined as the conversion time,
The activation energy deriving step obtains activation energy when the component is desorbed from the solid sample from the first time represented by the conversion time and the predetermined positive number. Thermal desorption analysis method. The temperature-programmed desorption analysis method according to claim 1,
The second time is a time later than the first time among the times indicating signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1,
In the time conversion step, the second time is represented by the conversion time, where the first time is 0,
The activation energy deriving step obtains activation energy when the component is desorbed from the solid sample from the second time represented by the conversion time and the predetermined positive number. Thermal desorption analysis method. In the temperature-programmed desorption analysis method according to any one of claims 1 to 3 ,
The temperature programmed desorption analysis method, wherein the predetermined positive number is 0.5. Temperature control means for controlling the temperature of the solid sample in accordance with a temperature program that heats the solid sample and sets the temperature as a function that increases in inverse proportion to the linear expression of time from the temperature at time 0 ;
Detection means for detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals;
First extraction means for extracting a maximum value of the signal intensity and a first time at which the signal intensity shows a maximum value;
Second extraction means for extracting a second time indicating a signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1;
The time at which the second time is 0 is defined as the conversion time, and the first time is represented by the conversion time, or the time at which the first time is 0 is defined as the conversion time, and the conversion time is the first time. Time conversion means for representing the time of 2;
When the component desorbs from the solid sample from the first time represented by the conversion time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number. A temperature-programmed desorption analyzer comprising: activation energy deriving means for obtaining activation energy. The temperature-programmed desorption analyzer according to claim 5 ,
The second time is a time earlier than the first time among the times indicating signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1,
The time conversion means uses the time when the second time is 0 as the conversion time, and the conversion time represents the first time,
The activation energy deriving means obtains activation energy when the component is desorbed from the solid sample from the first time represented by the conversion time and the predetermined positive number. Thermal desorption analyzer. The temperature-programmed desorption analyzer according to claim 5 ,
The second time is a time later than the first time among the times indicating signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1,
The time conversion means uses the time when the first time is 0 as the conversion time, and represents the second time as the conversion time,
The activation energy deriving means obtains activation energy when the component is desorbed from the solid sample from the second time represented by the conversion time and the predetermined positive number. Thermal desorption analyzer. The temperature programmed desorption analyzer according to any one of claims 5 to 7 ,
A temperature-programmed desorption analyzer characterized in that the predetermined positive number is 0.5. A temperature control step of controlling the temperature of the solid sample in accordance with a temperature program that heats the solid sample and functions as a function that increases the temperature from the temperature at time 0 in inverse proportion to the linear expression of time;
A detection step of detecting a signal intensity proportional to the amount of the component desorbed from the solid sample at regular intervals;
A first extraction step of extracting a maximum value of the signal intensity and a first time at which the signal intensity shows a maximum value;
A second extraction step of extracting a second time indicating a signal intensity obtained by multiplying the maximum value by a predetermined positive number smaller than 1;
The time at which the second time is 0 is defined as the conversion time, and the first time is represented by the conversion time, or the time at which the first time is 0 is defined as the conversion time, and the conversion time is the first time. A time conversion step representing the time of 2;
When the component desorbs from the solid sample from the first time represented by the conversion time and the predetermined positive number, or from the second time represented by the conversion time and the predetermined positive number. A thermal desorption analysis program that causes a computer to execute an activation energy deriving step for obtaining activation energy.

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