JPS602746B2 - Sample cooling device for electron microscopes, etc. - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sample tilting device for an electron microscope or the like, and particularly to an improvement of a device for tilting a sample kept at a low temperature.

Generally, in electron microscopes, etc., a device with the structure shown in Figure 1 is widely used as a device that uses cold soot such as liquid helium to tilt the sample while the sample is cooled to an extremely low temperature. There is.

In the figure, reference numeral 1 denotes a cooling tank into which liquid helium 2 is introduced, and the cooling tank is attached via heat insulators 4a and 4b to a sample moving stage 3, which is movably covered with a thin layer over an objective lens (not shown). At the bottom of the cooling tank, two support legs 5a and 5b are provided opposite to each other and are suspended within the magnetic pole piece of the objective lens. There are two shafts 6a on the lower outer periphery of the support leg.
, 6b, the intermediate ring 7 of the jimpal mechanism is pivotally held. The axes of the two axes 6a and 6b are arranged on a straight line x-X' passing through the optical axis. A forehead diagonal body 9 is attached to the inside of the intermediate ring 7 via two shafts 8a and 8b.
are held on a flexible basis. Two cutouts 10a and 10b are formed on the outer periphery of the forehead oblique body, and the support legs 5a and 5b are arranged within the cutouts at an arbitrary interval. The axes of the two axes 8a and 8b are arranged on a straight line Y-Y' that passes through the optical axis and is perpendicular to the straight line x-X'. A sample cylinder 12 holding a sample 11 is removably attached to the center of the inclined body 9, and two drive rods 13a and 13b (indicated by dotted lines in FIG. 2) are attached to the inclined body. ) are respectively engaged. Accordingly, if the drive bar 13a is moved in the direction perpendicular to the plane of the paper in FIG.
, 8b and the intermediate ring, the sample 11 is framed with the x axis as the center. Furthermore, if one of the drive shafts 13b is moved, the oblique body 9 moves around the shafts 8a and 8b, so that the sample is centered around the Y bush. As a result, by arbitrarily operating the two drive rods 13a and 13b, the sample 11 can be tilted in any direction and at any angle. Since the sample 11 must be kept at an extremely low temperature, the cooling bath 1 and the forehead diagonal body 9 are thermally connected by a flexible heat conductor bent in a U-shape indicated by the reference numeral 14 in FIG. It's forcing me. However, in this way the space between the cooling tank and the oblique body is
When a sample is repeatedly tilted in a device connected by a letter-shaped heat conductor, the heat conductor is subjected to large bending and twisting at the same time, which makes it susceptible to fatigue failure, and a large resistance force is generated. It becomes a hindrance.

In order to solve these problems, the present invention provides a device in which only a small twisting deformation occurs in the heat conductor, and will be described in detail below with reference to the drawings.

Note that the same numbers as in FIGS. 1 and 2 indicate the same components.
FIG. 3 is a perspective view of the bottom of the inclined body showing an embodiment of the present invention, and 15a to 15d are thermal conductors made of, for example, copper or silver for thermally connecting the cooling tank 1 and the inclined body 9. In the body, the heat conductor is formed into a thin and elongated strip having a thickness of, for example, about 0.1 mm, and is made to be maneuverable.

In addition, these heat conductors are bent so that both ends thereof face substantially perpendicular to each other, and arranged so as to be included in a plane parallel to and close to the plane defined by the tilt axes x and Y, Projections provided at both ends are fixed to the bottom of the support leg and the bottom of the ramp, respectively. That is, the thermal conductors 15a, 15b
One of the protrusions 16a and 17a is fixed to the bottom of the support leg 5a by screws 18a and 18b, and the other protrusion 16
b, 17b are fixed to the bottom of the inclined body 9 by screws 18c, 18d. At this time, the attachment positions of both heat conductors 15a and 15b to the support leg 5a are on the X axis, and the attachment positions of both heat conductors to the inclined body 9 are on opposite sides with respect to the optical axis. It is placed on the Y axis. One of the remaining heat conductors 15c and 15d has protrusions 19a and 20a attached to the screw 1.
It is fixed to the bottom of the support leg 5b by 8e and 18f, and the other protrusion 19b and 20b is fixed to the bottom of the diagonal mirror body 9 by screws 18g and 18h. At this time, both heat conductors 1
5c and 15d are attached to the support leg 5b on the x mouse, and the attachment positions of both heat conductors to the inclined body 9 are on opposite sides of the optical axis and on the Y axis. ing. However, when the tilting body 9 is moved around the X axis, for example,
In each heat conductor, since it is arranged so as to be included in a plane parallel to and close to the plane defined by the oblique axis is only twisted.

At this time, since each heat conductor is installed at the bottom of the inclined body 9, it can be brought close to the oblique axis, and therefore there is almost no curling of the heat conductors. Furthermore, when the inclined body 9 is laid out around the Y-axis, twisting occurs in the side surface of each heat conductor on the side fixed to the forehead oblique body. Note that the thermal conductors 15a to 15d are fixed as close to the center of the tilted ball as possible, so if the bottom surface of the tilted body 9 is flat, this tilted body can be
Even a slight tilt about the axis causes the bottom of the tilted body to collide with the heat conductors 15a to 15d fixed to the support legs 5a and 5b, making it impossible to tilt the forehead.

Therefore, as shown in FIG. 3, a concave portion 21 is formed at the bottom of the dovetail body 9 so that the oblique angle of the dovetail body 9 can be made as large as possible. With the above configuration, the present invention can reduce the deformation of the thermal conductor to only a small twist when the sample is tilted, thereby eliminating fatigue failure and reducing the resistance force generated in the thermal conductor. It has great practical effects, such as being able to tilt the sample smoothly.

It should be noted that the above description is an illustration of the present invention, and many modifications may be made in implementing the present invention.

For example, although the case where four thermal conductors are used is shown, one or more thermal conductors may be used.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view showing a conventional example, and Figure 2 is A-A in Figure 1.
A sectional view and FIG. 3 are perspective views showing one embodiment of the present invention. In FIG. 3, 5a and 5b are supporting legs, 9 is a tilting body, 1
5a to 15d are thermal conductors, 16a, 16b, 17a,
17b, 19a, 19b, 20a and 20b are protrusions;
18a to 18h are screws, and 21 is a recess. Juice 1 diagram Ototsu soup 3 diagram

Claims (1)

[Claims] 1. A cooling tank, a sample holding member tiltably held by a pair of substantially orthogonal inclined shafts, and a flexible band-shaped heating member for thermally connecting the sample holding member to the cooling tank. a conductor, and when connecting the thermal conductor between the sample holding member and the cooling tank, the band-shaped thermal conductor is bent at a substantially right angle, and the surface is parallel to the plane defined by the pair of inclined axes. In an electron microscope or the like, the electron microscope is disposed in a plane close to the inclination axis, and one end thereof is attached to a position along one of the inclined axes, and the other end thereof is attached to a position along the other of the inclination axes. Sample cooling device.