JPH05281161A - X-ray diffraction apparatus - Google Patents

Abstract

PURPOSE:To enhance the freedom in the arrangement and the design of apparatuses and the like required for the measurement of X-rays and to achieve the compact configuration. CONSTITUTION:A sample supporting mechanism 9, which is provided in an X-ray diffraction apparatus, has a sample holding stage 15 and a first rotating arm 16. The sample holding stage 15 rotates the sample with an axial line phi, which passes the sample holding position P on the optical path of incident X-rays 11, as a rotary axis. The first rotating arm 16 rotates the sample holding stage 15 with an axial line chi, which passes through the sample holding position P and crosses the above described axial line phi at an acute angle alpha, as a rotary axis. Furthermore, a second rotating arm 17, which rotates the first rotating arm 16 is provided. In this case, an axial line omega, which passes the sample holding position P and crosses the axial line chi at the acute angle alpha, is used as a rotating axis.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
The present invention relates to an X-ray diffraction device suitable for acquiring a line diffraction image.

[0002]

2. Description of the Related Art For example, in the case of conducting a structural analysis of a polycrystalline sample, it is often required to obtain an X-ray diffraction image of a minute region having a diameter of 100 μm or less on the sample.

The number of crystal grains existing in the X-ray irradiation region decreases as the measurement region becomes smaller, and the crystal lattice of the crystal grains in the sample depends on how to select the micro region on the sample to be measured. There is a problem such as detection leakage due to the deviation of the directional distribution of the surface, and as a result, it is not possible to obtain a continuous diffraction spectrum without peak detection leakage, which may reduce the analysis accuracy.

Therefore, in the X-ray diffractometer for the purpose of acquiring the X-ray diffraction image of such a minute area, in order to avoid the occurrence of the inconvenience such as the detection omission due to the deviation of the directional distribution of the crystal lattice planes. In addition, it is indispensable to equip the sample support mechanism so that the direction of the sample on the optical path of the incident X-ray can be freely changed.

FIG. 2 shows a sample support mechanism in a conventional X-ray diffraction apparatus which uses a position-sensitive X-ray detector as a means for detecting a diffraction line from a sample for the purpose of acquiring an X-ray diffraction image of a minute area. It is shown. This sample support mechanism is designed so that the orientation of the sample on the optical path of the incident X-ray can be freely changed. The sample holding mechanism holds the sample 2 at the sample holding position P on the optical path 1 of the incident X-ray. The shaft 3, the first rotation drive unit 4 for rotationally driving the sample holding shaft 3 as shown by the arrow (a) in the figure with the central axis A of the sample holding shaft 3 as the rotating shaft, and the sample holding position P are shown. The axis drive section 4 is swung (circulated) as shown by arrows (b) and (c) with the axis B (overlapping the optical path 1 in the figure) B passing therethrough as a rotation axis. The second rotation driving unit 5 is provided.

Although not described in detail, the second rotary drive unit 5 causes the first rotary drive unit 4 to travel on a circumferential guide member having the sample holding position P as the center of curvature. Is.

[0007]

In the sample support mechanism of the conventional X-ray diffraction apparatus described above, the rotation of the sample 2 by the first rotation drive unit 4 and the sample 2 by the second rotation drive unit 5 are performed.
By combining the above rotations, any minute area on the sample 2 can be directed to the incident X-ray. Therefore,
By performing the X-ray diffraction measurement while rotating the sample 2 by the first rotation drive unit 4 and the second rotation drive unit 5, the sample 2 is uniformly irradiated with X-rays from all directions, It is possible to avoid the occurrence of inconvenience such as detection omission due to the deviation of the directional distribution of the crystal lattice planes of the crystal grains in the sample, and therefore it is possible to obtain a continuous diffraction spectrum without omission of peak detection, It is possible to prevent a decrease in analysis accuracy.

However, in the above-described conventional sample support mechanism of the X-ray diffraction apparatus, the circumferential guide member of the second rotary drive unit 5 surrounds the sample 2 around the sample holding position P as the center of curvature. Therefore, this circumferential guide member is incident X
It is necessary to devise the setting of the path of incident X-rays and the arrangement of X-ray detectors so as not to block the X-rays and diffraction rays. There is a problem that the degree of freedom is low and the design of the X-ray diffraction device becomes difficult accordingly.

Further, because of the circumferential guide member of the second rotary drive unit 5 that surrounds the sample 2, the sample support mechanism becomes large, resulting in a compact X-ray diffractometer. There was also a problem that it would be difficult to make it.

The present invention has been made in view of the above circumstances, and does not require a circular guide member or the like surrounding the sample in the sample support mechanism. Therefore, the path design of the incident X-ray and the X-ray detector are performed. It is an object of the present invention to provide an X-ray diffractometer which has a high degree of freedom in the layout design of each device, and which is also suitable for making the device compact.

[0011]

An X-ray diffraction apparatus according to the present invention produces an incident X-ray that collimates an X-ray source and an X-ray output from the X-ray source and irradiates a minute region on a sample. Incident X-ray generation means, a sample support mechanism that supports the sample on the optical path of the incident X-rays generated by the incident X-ray generation means, and a position-sensitive X-ray detector that detects diffraction rays from the sample. And a processing device for processing the detection result of the position-sensitive X-ray detector.

The sample support mechanism includes a sample holder, a first rotary arm that supports the sample holder, and a second rotary arm that supports the first rotary arm. The sample holder includes a sample holding shaft that holds the sample at a sample holding position P on the optical path of the incident X-ray, and a first axis drive unit that rotationally drives the sample holding shaft with the central axis φ of the sample holding shaft as a rotation axis. And a structure in which the sample is rotated around the central axis φ.

Further, the first rotating arm rotates an axis χ that intersects the central axis φ and the acute angle α through the sample holding position P with the first arm member to which the sample holder is attached. As a shaft, a configuration is provided that includes a second shaft driving unit that rotationally drives the first arm member on the second rotary arm.

The second rotary arm has an axis ω that intersects with the second arm member, to which the first rotary arm is attached, through the sample holding position P and the axis χ at an acute angle α.
And a third shaft driving section that rotationally drives the second arm member with the rotation axis as a rotation axis.

The sample support mechanism of the X-ray diffractometer according to the present invention comprises:
Rotation of the sample about the axis φ by the sample holder,
By operating the rotation of the sample about the axis χ by the rotating arm and the rotation of the sample about the axis ω by the second rotating arm, a minute area on the sample irradiated with the incident X-ray is manipulated. The above-mentioned axes φ, χ, and ω intersect each other at an acute angle, and a mechanism that surrounds the circumference of the sample is not used.

Therefore, the periphery of the sample is opened to a greater extent, and the degree of freedom in designing the path of incident X-rays and the layout design of each device such as the X-ray detector is increased.
The design of the X-ray diffractometer can be facilitated. Also,
It is also possible to prevent the sample support mechanism itself from becoming large due to the mechanism that surrounds the periphery of the sample, which can be expected to make the X-ray diffractometer itself compact.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of the X-ray diffraction apparatus according to the present invention. The X-ray diffractometer of this embodiment is intended to obtain an X-ray diffraction image of a minute area on a polycrystalline sample, and collimates the X-ray source 7 and the X-rays output from the X-ray source 7. Incident X-ray generation means 8 for generating incident X-rays 11 for irradiating a minute region on the sample and a sample support for supporting the sample on the optical path of the incident X-rays 11 generated by the incident X-ray generation means 8. Mechanism 9, an optical microscope 10 for observing the irradiation position of incident X-rays 11 on the sample supported by the sample support mechanism 9, and a measurement position of a desired minute region on the sample using the optical microscope 10. Support mechanism position adjusting means (not shown) capable of finely adjusting the position of the sample support mechanism 9 in order to position the sample support mechanism 9, a position-sensitive X-ray detector 30 for detecting the diffraction line 12 from the sample, and this position Process the detection result of the sensitive X-ray detector 30. Management device 3
1 and a display device 32 for displaying the processing result of the processing device 31 (that is, the measurement result, etc.).

The X-ray source 7 is a so-called micro focus X-ray source, and as shown in FIG. 1, it has an electron gun 7a, focusing lenses 7b and 7c, and a target 7d.
For example, an X-ray is generated when an electron beam focused on a micro focus of several tens of μm collides with the target 7d.

The incident X-ray generating means 8 is a so-called collimator, and is suitable for spot-irradiating the X-ray output from the X-ray source 7 onto a minute area on the sample (for example, irradiation with a spot having a diameter of about 100 μm). It is shaped into a thin X-ray beam.

The sample support mechanism 9 comprises a sample holder 15
And a first rotary arm 16 that supports the sample holder 15.
And a second rotary arm 17 that supports the first rotary arm 16.
It consists of and.

Here, the sample holder 15 has a sample holding shaft 20 for holding the sample at a sample holding position P on the optical path of the incident X-ray 11 and a central axis φ of the sample holding shaft 20 as a rotation axis. A first axis drive unit 2 that rotationally drives a sample holding shaft 20.
1, and the sample is rotated around the central axis φ.

The first rotary arm 16 has an axis χ which intersects the central axis φ at an acute angle α through the sample holding position P and the first arm member 23 to which the sample holder 15 is attached. A sample supported by the sample holder 15 is held by the sample holding table 15 with a configuration including a second shaft driving unit 24 that rotationally drives the first arm member 23 on the second rotating arm 17 as a rotating shaft. It is rotated around the axis χ together with the table 15.

The second rotary arm 17 has an axis ω that intersects with the second arm member 26, to which the first rotary arm 16 is attached, through the sample holding position P and the axis χ at an acute angle α. And a third shaft driving unit 27 that rotationally drives the second arm member 26 with the rotation axis as the rotation axis, and the sample is rotated around the axis ω together with the sample holding table 15 and the first rotation arm 16. Rotate.

In FIG. 1, the central axis φ and the axis ω overlap each other, but the axes φ, χ, and ω are individual as shown in FIG.

The central axis φ is rotatable about the axis χ in the state of intersecting the axis χ at an angle α at the sample holding position P. Further, the axis χ is capable of turning around the axis ω in a state of intersecting the axis ω at an angle α at the sample holding position P.

As shown in FIG. 4, the optical microscope 10 observes the X-ray irradiation position on the sample via a mirror 35 supported by a mirror support 34. Mirror support 3
Reference numeral 4 is connected to a rotary shaft 37 having a knob 36, and a state in which the mirror 35 is positioned on the optical path of the incident X-ray 11 by rotating the knob 36 to rotate around the rotary shaft 37. , Or the mirror 35 to the incident X-ray 1
It is possible to switch from the first optical path to the retracted state (FIG. 1 shows the retracted state, and FIG. 4 shows the advanced state on the optical path).

The mirror 35 has a reflecting surface that forms an angle of 45 degrees with respect to the optical path of the incident X-ray 11 when it advances into the optical path of the incident X-ray 11, and is in a direction orthogonal to the incident X-ray 11. It enables observation of the sample from the optical microscope 10 whose optical axis is set to. This mirror 35 is incident X only when the sample is observed by the optical microscope 10 for the purpose of aligning the sample.
When the measurement is performed by advancing on the optical path of the line 11 and irradiating the sample with X-rays, the sample is retracted from the optical path of the incident X-ray 11.

A support mechanism position adjusting means (not shown) for finely adjusting the position of the sample support mechanism 9 observes the sample surface with the optical microscope 10 through the mirror 35, and the optical microscope 1
The position of the sample support mechanism 9 is adjusted so that the microscopic region of the sample to be measured overlaps the cross position of the crosshairs provided in 0 and the optical microscope image becomes clear. The position of the sample set by this support mechanism position adjusting means is
It is unchanged even when the sample supporting mechanism 9 rotates the sample about the φ axis, the χ axis, and the ω axis.

As the position sensitive X-ray detector 30,
For example, the configuration shown in FIGS. 5 and 6 can be considered. That is, the position-sensitive X-ray detector 30 includes the X-ray entrance window 4
An outer cylinder 41 having 0, and the X in the outer cylinder 41.
A drift field setting cathode 42, a grid 43, and an anode 44, which are electrodes provided along the line incidence window 40, and a large number of reading cathodes arranged at regular intervals in a direction perpendicular to these electrodes. 45a, 45b, ..., 45
n, a delay line 46 for electrically connecting adjacent cathodes of the cathodes 45a, 45b, ..., 45n, and lead wires 47a, 47b for signal extraction connected to both ends of the delay line 46. , Amplifiers 48a and 48b for amplifying the signals of these lead wires 47a and 47b, waveform shaping circuits 49a and 49b for shaping the waveforms of the signals amplified by these amplifiers 48a and 48b, and these waveform shaping circuits 49a, A time difference intensity conversion circuit 50 that receives the output signal of 49b and generates a signal having an intensity corresponding to the time difference between the signals, and an A / D conversion circuit 51 that digitizes the signal generated by the time difference intensity conversion circuit 50, It is composed of a memory circuit 52 for storing the output data of the A / D conversion circuit 51 as a position signal.

The above-mentioned drift electric field setting cathode 4 is used.
The electrodes such as 2, the grid 43 and the anode 44 are obtained by stretching a wire of tungsten or stainless along the X-ray entrance window 40 in the outer cylinder 41. Further, in the outer cylinder 41, the inflow port 41a on one end side is provided.
A predetermined reaction gas is introduced, and the outlet 41b on the other end side is introduced.
Is discharged from.

In the position-sensitive X-ray detector 30 having the above structure, when X-rays enter through the X-ray entrance window 40, the reaction gas molecules are ionized, and the electrons generated by this initial ionization are generated between the electrodes. When it is accelerated by the electrostatic field and reaches the vicinity of the anode 44, a local avalanche phenomenon occurs and the anode 4
Captured by 4. When this avalanche phenomenon occurs, a positive pulse voltage is induced in the adjacent read cathode, and the signal is taken out from both ends of the delay line 46. However,
When the position where the avalanche phenomenon occurs, that is, the X-ray incidence position is not equal from both ends of the delay line 46, the signals from both ends of the delay line 46 are extracted with a time shift. This signal is sent to the waveform shaping circuits 49a, 49b via the amplifiers 48a, 48b, shaped into signals showing a sharp rise, and then sent to the time difference intensity conversion circuit 50 as a start or stop signal. The output of the time difference intensity conversion circuit 50 has an intensity corresponding to the time difference between the signals from the waveform shaping circuits 49a and 49b, is digitized by the A / D conversion circuit 51, and is stored as a position signal in the memory circuit 52. Memorized in. When the output signals of the A / D conversion circuit 51 have the same intensity, the memory circuit 52 integrates and stores the same at the same address. Therefore, when a large number of X-ray photons are incident on the same point on the position-sensitive X-ray detector 30, the memory circuit 52 stores the integrated signal according to the number. The signal stored in the memory circuit 52 is read out by the processing device 31 after the measurement is completed and subjected to a predetermined display process or analysis process.

The position-sensitive X-ray detector 30 itself is
It is not limited to the structure of one embodiment. For example, an imaging plate in which a phosphor layer that absorbs / accumulates radiation and emits stimulated emission depending on the intensity of the accumulated radiation when irradiated with excitation light is formed on the surface of the substrate facing the diffraction line 12 is adopted. It may be done. Further, the shape of the position-sensitive X-ray detector 30 is not limited to that of the embodiment, and a spherical shell shape having the sample holding position P as the center of curvature or a flat plate shape can be considered.

The processing device 31 has 16 bits or 3 bits.
A computer equipped with a 2-bit CPU is used to perform processing for obtaining an X-ray diffraction image in accordance with the signal detected by the position-sensitive X-ray detector 30.

The display device 32 uses a CRT or the like, and displays the processing result of the processing device 31 on the screen.

In the X-ray diffractometer according to the above-described embodiment, the sample support mechanism 9 mounted therein rotates the sample by the sample holder 15 and rotates the sample by the first rotating arm 16. By combining with the rotation of the sample by the second rotating arm 17, it is possible to direct an arbitrary minute region on the sample to the incident X-ray 11. Therefore, by performing the X-ray diffraction measurement while rotating the sample by the sample holder 15, the first rotary arm 16, and the second rotary arm 17, the sample supported at the sample holding position P is not affected. It is possible to irradiate X-rays evenly from all directions, and to avoid the occurrence of inconvenience such as detection failure due to biased distribution of the crystal lattice planes of the crystal grains in the sample. Therefore, there is no peak detection failure. It is possible to obtain continuous diffraction spectra and prevent deterioration of analysis accuracy.

Moreover, in the sample support mechanism 9 in the above-described embodiment, the micro area on the sample irradiated with the incident X-rays 11 by the three rotation axis lines φ, χ, ω intersecting at an acute angle at the sample holding position P. It is operated and does not use a mechanism that surrounds the circumference of the sample.

Therefore, as compared with the conventional one as shown in FIG. 2, the periphery of the sample is largely opened, and the path design of the incident X-ray and the position-sensitive X-ray detector 30 and the like of each device are performed. The degree of freedom in the layout design is increased, and the X-ray diffractometer can be easily designed accordingly. In addition, it is possible to prevent the sample support mechanism 9 itself from becoming large due to a mechanism that surrounds the periphery of the sample, and it can be expected that the X-ray diffraction apparatus can be made compact.

In the embodiment described above, the first arm member 2
Each of the third arm member 26 and the second arm member 26 is formed as a block having a bent integral structure by cutting a metal material. However, the shapes and materials of these arm members 23, 26, and the processing method are not limited to the one embodiment. The arm members 23 and 26 themselves may have a desired bent structure by a combination of a plurality of parts, or may have a predetermined structure by injection molding using synthetic resin or the like. ..

[0038]

As is apparent from the above description, in the sample support mechanism of the X-ray diffraction apparatus according to the present invention, the sample holder rotates the sample about the axis φ and the axis χ by the first rotating arm. By operating the rotation of the sample around it and the rotation of the sample about the axis ω by the second rotating arm, a small area on the sample irradiated with the incident X-ray is manipulated. , Χ, and ω intersect each other at an acute angle, and a mechanism that surrounds the sample is not used. Therefore, the periphery of the sample is opened more largely, and the path design of incident X-rays and X
The degree of freedom in the layout design of each device such as the line detector is increased, and the design of the X-ray diffraction apparatus can be facilitated accordingly. In addition, it is possible to prevent the sample support mechanism itself from becoming large due to a mechanism that surrounds the periphery of the sample, and it can be expected that the X-ray diffraction apparatus itself can be made compact.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of an X-ray diffractometer according to the present invention.

FIG. 2 is an explanatory diagram of a conventional sample support mechanism.

FIG. 3 is a vertical cross-sectional view of a main part of an embodiment of the present invention.

FIG. 4 is a view from the direction of arrow A in FIG.

FIG. 5 is a structural explanatory view of a position-sensitive X-ray detector of one embodiment of the present invention.

FIG. 6 is a structural explanatory view of a position-sensitive X-ray detector of one embodiment of the present invention.

[Explanation of symbols]

 7 X-ray source 8 Incident X-ray generation means 9 Sample support mechanism 10 X-ray output means 11 Incident X-ray 12 Diffraction line 15 Sample holder 16 First rotating arm 17 Second rotating arm 20 Sample holding shaft 21 First axis Drive unit 23 First arm member 24 Second axis drive unit 26 Second arm member 27 Third axis drive unit φ, χ, ω axis 30 Position sensitive X-ray detector 31 Processor 32 Display device

Claims (1)

[Claims] 1. An X-ray source, an incident X-ray generation unit that collimates the X-ray output from the X-ray source, and generates an incident X-ray that irradiates a minute area on a sample, and the incident X-ray generation unit. A sample supporting mechanism for supporting the sample on the optical path of the incident X-ray generated by the above, a position-sensitive X-ray detector for detecting the diffraction line from the sample, and a detection result of the position-sensitive X-ray detector. An X-ray diffractometer including a processing device for processing, wherein the sample supporting mechanism holds a sample holding shaft for holding a sample at a sample holding position P on an optical path of incident X-rays, and a central axis line of the sample holding shaft. A sample holder that includes a first shaft driving unit that rotates and drives the sample holding shaft with φ as a rotation axis, and that rotates the sample around the central axis φ, and a first rotating arm that supports the sample holder. And a second rotary arm that supports the first rotary arm, The first rotary arm has a first arm member to which the sample holder is attached and the second arm with an axis χ that intersects the central axis φ at an acute angle α through the sample holding position P as a rotation axis. A second arm for rotationally driving the first arm member on the rotary arm
And a second arm, to which the first rotary arm is attached, passing through the sample holding position P and forming an acute angle α with the axis χ. An X-ray diffraction apparatus having a configuration including a third axis drive unit that rotationally drives the second arm member with an intersecting axis line ω as a rotation axis.