JPH076928B2 - Electromagnetic diffraction device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electromagnetic diffraction device, and particularly to a semiconductor detector or the like characterized by being arranged in close contact with an incident ray bundle of electromagnetic waves such as X-rays. The present invention relates to an electromagnetic ray diffraction device including an electromagnetic wave detector.

[Conventional technology]

Conventionally, for measuring the lattice constant a of a natural crystal that is a three-dimensional lattice, for example, characteristic X-rays of copper (wavelength λ = 0.15405980 nm) are used.
Was diffracted by a diffractive surface having a specific lattice spacing d, and the diffraction angle θ was accurately measured. The Bond method is one example, but the accuracy is good even if it is good.
It was 1 × 10 ⁻⁷ as d / d. In addition, Δd represents a measurement error of d.

[Problems to be solved by the invention]

As shown in 2d sin θ = n λ,
It is shown that if the wavelength λ can take an arbitrary value, the most accurate lattice spacing d can be measured when the diffraction angle θ is close to 90 degrees. However, since a characteristic X-ray having a specific wavelength λ which is a material constant and a diffraction surface of a crystal having a fixed lattice spacing d are used, there is a serious limitation that the diffraction angle θ cannot always be measured near 90 degrees.

SUMMARY OF THE INVENTION It is an object of the present invention to eliminate the above-mentioned drawbacks, and to provide an electromagnetic ray diffractometer capable of measuring a diffraction angle of nearly 90 degrees, which has heretofore been generally impossible, with high accuracy.

[Means for solving problems]

In order to achieve the above object, the present invention provides a white X-ray generation means for generating white X-rays having a continuous wavelength with high brightness such as synchrotron radiation, and a lattice type sample having a lattice constant to be measured. A monochromator that selects from the white X-rays X-rays of a specific wavelength that causes diffraction of nearly 90 degrees on the grating plane, and a pinhole-type collimator that passes incident X-rays of the specific wavelength from the monochromator, Position sensitive to be placed in close proximity to the pinhole type collimator and to detect the diffracted electromagnetic wave which the incident X-ray of the specific wavelength passing through the pinhole type collimator is diffracted by the grating type sample at a diffraction angle close to 90 degrees. Type electromagnetic wave detecting means.

[Action]

In the present invention, the wavelength of the incident electromagnetic wave (X-ray) is arbitrarily selected by the monochromator according to the diffractive surface spacing d of the sample to form a diffraction angle of about 90 degrees, and the diffracted X-ray is extremely minutely close to the incident line. Received light is detected by the position-sensitive electromagnetic wave detector.

As described above, according to the present invention, since the diffraction angle can be accurately measured near 90 degrees, the lattice spacing can be measured with high accuracy. That is, according to the present invention, the deviation of the crystal lattice constant from a certain reference value can be measured with high accuracy, for example, by one digit as compared with the result obtained by the conventional method.

〔Example〕

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of the present invention. In this figure, white X-rays 2 emitted from a powerful white X-ray source 1 having a continuous wavelength with high brightness like synchrotron radiation.
Is an X of a specific wavelength λ which is dispersed by an appropriate monochromator, preferably a 4-crystal monochromator 3, and causes diffraction of nearly 90 degrees at the lattice plane of a sample crystal (lattice type sample) 6 having a lattice constant to be measured. It becomes a line (monochromatic X-ray) 4. This X
The line 4 is made into a parallel line bundle by the pinhole type collimator 5 and is incident on the sample crystal 6. The four-crystal monochromator 3 is made of two sets cut from one Ge single crystal by a channel cut, and using this (440) reflection, an incident X-ray with a divergence angle of about 5 seconds can be obtained. As a result, sharp diffraction line peaks are obtained in both positive and negative reflections. The tip diameter of the pinhole type collimator 3 is 1 mm
The degree is enough.

When this sample crystal 6 is rotated around a rotation axis (sample rotation axis) 9 included in the diffraction surface of the crystal, the diffracted X-rays 7 diffracted by the diffraction surface are the optical axes of the incident X-rays 4. Is incident on the solid-state electromagnetic wave detector 8 that is installed close to the optical axis and is perpendicular to the optical axis. The incident position is output and displayed on the multi-channel analyzer 11, for example. At this time, in order to make the diffraction angle θ of the sample crystal 6 close to 90 degrees, the angle formed by the incident X-ray 4 of the monochromator 3 (monochromator diffraction angle) 10
Can be adjusted to change the wavelength λ of the X-ray 4 appropriately. The solid-state electromagnetic wave detector 8 is a curved position-sensitive electromagnetic wave detector, and has a radius centered on the rotation axis of the sample crystal 4 as a part of an arc depending on a distance between the rotation axis and the surface of the detector 8. .

As described above, since the white X-rays 2 having a continuous wavelength with high brightness such as synchrotron radiation are used, the wavelength that matches the lattice constant can be selected. The selection of this wavelength can be obtained by adjusting the angle of the monochromator 3 as described above. Further, since the pinhole type collimator 3 and the position sensitive type electromagnetic wave detector 8 are used to form the passage of the incident X-ray in close contact with the semiconductor detection element, the blind spot can be limited to 2 mm or less. Therefore, the Bragg angle is 89.
You will get 8 degrees. If the Bragg angle can be 89.8 degrees and the Bragg angle determination accuracy is the same for 1 second compared to 87.5 degrees, the lattice constant can be determined with an accuracy of one digit or more as follows (wavelength at this time is 1.98892A). Was used).

Bragg angle Change of lattice constant with 1 second change (Δd) 87.5 degrees 1.9 × 10 ^-7 A 89.8 degrees 1.5 × 10 ^-8 A Thus, the diffraction X-rays are captured as close to 90 degrees of the Bragg angle as possible. The constant can be measured with extremely high accuracy.

FIG. 2 shows a configuration example on the detection surface side of the solid-state electromagnetic wave detector 8 described above. As shown in the figure, the above-mentioned X-ray 4 passes through the collimator 5, passes through the hole-shaped passage 12 through which the incident X-ray 4 passes in the front direction perpendicular to the paper surface, and the sample crystal 6 placed in front of the paper surface. (See FIG. 1). Diffracted X-rays 7 (see FIG. 1) diffracted by the sample crystal 6 are incident on, for example, 15 or 16 points of a one-dimensional position-sensitive semiconductor detector group (sensor array) 14 which is in close contact with the passage 12. Then, the incident point is accurately detected.

If such an electromagnetic wave detector 8 is arranged in the X-ray diffractometer as shown in FIG. 1, the distance between the electromagnetic wave detector 8 and the rotating shaft 9
By fixing the angle 10 formed between the monochromator 3 and the incident X-ray 4, the lattice spacing of different sample crystals having a value d ± Δd close to the lattice spacing d of the sample crystal 6 can be relatively accurately measured. It can be measured.

At present, a position sensitive type semiconductor detector having a relatively high position resolution of about 10 μm is provided. For example, the line width of the incident X-ray 4 is set to 0.1 mm and the electromagnetic wave detector 8 is used.
If the distance between the rotary shaft 9 and the rotary shaft 9 is 400 mm, and the half width of the line X-ray 7 is an angle of 10 seconds at most, a diffraction angle of about 89.95 degrees can be obtained, and the measurement accuracy is Δd / d of 5 × 10 ^-8. It becomes possible to measure with the accuracy of.

In addition, although the X-ray diffracting device is illustrated in the above-mentioned embodiment, the present invention is not limited to this, and is applicable to, for example, an electron beam or neutron beam diffracting device.

Furthermore, regarding the electromagnetic wave detector 8, as shown in FIG.
Instead of the hole-shaped passage 12 described above, a gap-shaped passage 16 may be provided, and the detector group 14 may be arranged around the passage 16.

〔The invention's effect〕

As described above, according to the present invention, a white X-ray having a continuous wavelength with high brightness such as synchrotron radiation is used, and a pinhole collimator and a position sensitive electromagnetic wave detector are used. By making a path for incident X-rays close to the semiconductor detection element, it is possible to accurately measure a diffraction angle of nearly 90 degrees, which was generally impossible in the past, with a position-sensitive detector close to the incident line. As a result, it is possible to obtain a highly accurate electromagnetic beam diffraction device that can measure the deviation of the crystal lattice constant from a certain reference value with an accuracy as high as one digit as compared with the result obtained by the conventional method.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view showing the configuration of an embodiment of an electromagnetic diffraction apparatus of the present invention, FIG. 2 is a detailed front view of the detector portion of FIG. 1, and FIG. FIG. 7 is a front view of another embodiment of the detector portion of FIG. 1. 1 ... X-ray source, 2 ... white X-ray, 3 ... monochromator, 4 ... monochromatic X-ray (incident X-ray), 5 ... collimator, 6 ... sample, 7 ... diffraction X-ray, 8: Position sensitive electromagnetic wave detector, 9: Sample rotation axis, 10: Monochromator diffraction angle, 11: Multi-channel analyzer, 12: Incident X-ray hole passage, 14: One-dimensional position Sensitive semiconductor detector group, 15,16 ... Injection point of diffracted X-rays on the detector, 17 ... Gap-shaped passage of incident X-rays.

Claims (1)

[Claims] 1. A white X-ray generating means for generating white X-rays having a continuous wavelength of high brightness such as synchrotron radiation, and a lattice plane of a lattice type sample having a lattice constant to be measured is close to 90 degrees. A monochromator that selects X-rays of a specific wavelength that causes diffraction of the white X-rays, a pinhole-type collimator that transmits incident X-rays of the specific wavelength from the monochromator, and a pinhole-type collimator And the incident X of the specific wavelength passing through the pinhole collimator.
A position-sensitive electromagnetic wave detecting means for detecting a diffracted electromagnetic wave in which a line is diffracted by the grating type sample at a diffraction angle close to 90 degrees, and an electromagnetic ray diffracting apparatus.