JP2000146872A - X-ray diffractometer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To irradiate a sample with an incident X-ray of optional wave-length to easily conduct various kinds of X-ray diffraction measurement, by using continuous X-rays generated from an X-ray tube. SOLUTION: Continuous X-rays emitted from an X-ray tube 7 are taken out as a parallel X-ray beam using a capillary bundle 1, and the X-ray of specified wave-length (i.e., specified energy) is taken out from the parallel X-ray beam using a monochromater 8 to irradiate a sample S. A diffracted X-ray generated in the sample S is converged by a solar slit 9 to be received by an X-ray detector 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention
X-ray diffractometer that detects diffracted X-rays diffracted from a sample when X-rays are incident on the X-ray diffractometer and measures the physical characteristics and the like of the sample. The present invention relates to an X-ray diffractometer suitable for measuring the stress of a specimen.

[0002]

2. Description of the Related Art In recent years, attention has been paid to X-ray diffraction measurement using anomalous dispersion of X-rays. Anomalous dispersion of X-rays occurs remarkably when the wavelength of X-rays incident on a sample is near the absorption edge of atoms contained in the sample. General X-ray diffraction measurement method are the analytical method utilizing scattering orbital electron (normal dispersion) _phenomenon, and a substance atomic number close as 22 Ti and ₂₃ V and ₂₆ Fe and ₂₇ Co For the sample,
It was difficult to extract information on each constituent substance independently.

On the other hand, when the wavelength (energy) of incident X-rays is measured near the absorption edge of a constituent material, a remarkable anomalous dispersion is observed for each constituent material, so that atomic numbers close to each other are measured. Even for substances, it is possible to extract each information independently. Focusing on such a point is “X-ray diffraction measurement using anomalous dispersion of X-rays”.

In addition to X-ray diffraction measurement using anomalous dispersion of X-rays, attention is paid to the fact that the distance between crystal lattice planes of a sample changes depending on the magnitude and direction of stress in the sample. 2. Description of the Related Art A stress measurement method for detecting a change in the plane spacing based on a change in the diffraction angle of X-rays has attracted attention as an application field of X-ray diffraction measurement (for example, see Japanese Patent Application Laid-Open No. 7-280668).

[0005]

Now, in order to extract information on each constituent material of the sample by the X-ray diffraction measurement utilizing the above-mentioned anomalous dispersion of X-rays, it is necessary to correspond to the vicinity of the absorption edge of those constituent materials. The sample must be irradiated with X-rays of various wavelengths.

In the stress measurement, the change in the crystal lattice spacing can be observed as a larger angle change as the diffraction angle of the diffracted X-ray to be measured is larger. Therefore, the wavelength of the incident X-ray is appropriately adjusted according to the sample. Need to be changed.

In the conventional X-ray diffractometer, only the characteristic X-rays having high intensity among the X-rays radiated from the X-ray source are used. Therefore, the characteristics defined by the metal forming the target of the X-ray source are used. X-ray diffraction measurements could only be performed at the X-ray wavelength.

In order to change the wavelength of the incident X-ray (characteristic X-ray), the X-ray tube itself must be replaced. Re-adjustment of the vessel is labor- and time-consuming and inefficient. In particular, it has been practically difficult to cope with the above-described X-ray diffraction measurement and stress measurement using the anomalous dispersion of X-rays by replacing the X-ray tube.

The present invention has been made in view of such circumstances, and utilizes continuous X-rays generated by an X-ray source to irradiate a sample with incident X-rays of an arbitrary wavelength to perform various types of X-ray diffraction. An object of the present invention is to provide an X-ray diffractometer capable of easily performing a measurement.

[0010]

In order to achieve the above object, a first X-ray diffraction apparatus according to the present invention has the following configuration. (A) X-ray source that emits X-rays (b) Capillary bundle for extracting emitted X-rays as a parallel X-ray beam (c) Receiving the parallel X-ray beam and selecting a parallel X-ray beam of a specific wavelength (D) X-ray converging means for converging diffracted X-rays diffracted from a sample when a parallel X-ray beam of a specific wavelength is incident on the sample at a predetermined angle. X-ray detector for detecting the intensity of diffracted X-rays

A second X-ray diffraction apparatus according to the present invention has the following configuration. (A) X-ray source that emits X-rays (b) Capillary bundle for extracting emitted X-rays as a parallel X-ray beam (c) Diffraction from the sample when the parallel X-ray beam is incident on the sample at a predetermined angle X-ray converging means for converging diffracted X-rays. (D) An X-ray detector having a wavelength selection function of receiving the converged diffracted X-rays and detecting the intensity of the diffracted X-rays of a specific wavelength.

Further, a third X-ray diffraction apparatus according to the present invention has the following configuration. (A) X-ray source that emits X-rays (b) Capillary bundle for extracting emitted X-rays as a parallel X-ray beam (c) Diffraction from the sample when the parallel X-ray beam is incident on the sample at a predetermined angle X-ray converging means for converging the diffracted X-rays received. (D) Wavelength selecting means for receiving diffracted X-rays and selecting and emitting diffracted X-rays of a specific wavelength. (E) Specific converged and wavelength-selected. X-ray detector for detecting the intensity of diffracted X-rays of wavelength

In the above configuration, the “capillary bundle” is an optical element for emitting continuous X-rays emitted from an X-ray source as a parallel X-ray beam. This capillary bundle can be formed as shown in FIG. 4 using, for example, a capillary tube having a small diameter and an appropriate length (for example, a glass capillary tube). The capillary bundle 1 shown in FIG.
It is formed by bundling a plurality of glass capillary tubes 2 having an inner diameter of about 10 to 20 μm, each of which is bent with a parabolic curvature.

The capillary bundle 1 has a larger cross-sectional area from the end face 1a on the X-ray incidence side to the end face 1b on the X-ray emission side. For example, the incident side end face 1a is 16 mm ×
It is formed in a square shape of 16 mm, and the emission side end face 1 b is 20 mm.
The glass capillary tube 2 is formed in a square shape of mm × 20 mm, and the length from the incident side end face 1a to the exit side end face 1b is set to, for example, 80 mm.

If this capillary bundle 1 is used, the continuous X-ray R1 radiated from the X-ray focal point F and diverging is converted into the incident-side end face 1
a, and the parallel X-ray beam R
2 can be taken out. The continuous X-ray R1 is taken into the individual glass capillary tubes 2 from the incident side end face 1a, propagates while totally reflecting inside the glass capillary tubes 2, and then is emitted from the emission side end 1b to the outside. The X-ray R1 is extracted from the emission end face 1b as a parallel X-ray beam R2 having a high intensity with almost no attenuation.

Note that the capillary bundle 1 can be installed outside the X-ray source, as well as inside the X-ray source. At least the incident side end 1a of the capillary bundle 1 is X
When inserted into the inside of the radiation source and brought close to the X-ray focal point F, most of continuous X-rays radiated from the X-ray focal point and diverging can be taken into the capillary bundle 1, so that the X-ray intensity can be increased. Can be.

In the above-mentioned first X-ray diffraction apparatus according to the present invention, continuous X-rays radiated from an X-ray source are extracted as a parallel X-ray beam by a capillary bundle, and the parallel X-rays are acted on by a wavelength selecting means. X-rays of a specific wavelength (ie, specific energy) are extracted from the beam. And
The sample is irradiated with the parallel X-ray beam having the specific wavelength.

As is well known, the X-ray diffractometer has a goniometer, and the same applies to the X-ray diffractometer of the present invention. As a goniometer used in an X-ray diffractometer, for example, a θ-2θ goniometer and a θ-θ goniometer are known. The goniometer will be described with reference to a θ-2θ type goniometer. The goniometer rotates θ (so-called θ rotation) about a position immobile θ rotation axis.
It has a turntable and a 2θ turntable that also rotates at twice the angular velocity about the θ rotation axis in the same direction as the θ rotation.

The sample is supported on the θ-rotation table, while a component on the light-receiving side for diffracted X-rays, such as an X-ray detector, is supported on the 2θ-rotation table. When the incident angle θ of the X-ray irradiated on the sample reaches an angle that satisfies the so-called Bragg diffraction condition, diffracted X-ray is generated from the sample, and the diffracted X-ray is detected by the X-ray detector.

In the above-described first X-ray diffraction apparatus according to the present invention, a parallel X-ray beam having a specific wavelength selected by the wavelength selection means is extracted as a parallel X-ray beam by the capillary bundle, and is irradiated on the sample. Since the width of the parallel X-ray beam is large, the width of the diffracted X-ray generated from the sample is also wide. When the X-ray detector is used as it is, the resolution is low and it is difficult to obtain a highly accurate detection result. Therefore, in the present invention, diffracted X-rays generated in the sample are converged by the X-ray converging means and received by the X-ray detector.

In the X-ray diffraction measurement using the anomalous dispersion of X-rays described above, the sample must be irradiated with X-rays having a wavelength corresponding to the vicinity of the absorption edge of the constituent substance to be extracted. It is necessary to irradiate the sample with X-rays of a specific wavelength selected by the means. Therefore, the first X-ray diffraction apparatus according to the present invention is suitable.

In the second X-ray diffractometer according to the present invention, continuous X-rays emitted from an X-ray source are extracted as a parallel X-ray beam by a capillary bundle, and the parallel X-ray beam can be selected without wavelength selection. Irradiate the sample. For this reason,
Diffracted X-rays corresponding to each wavelength of the incident X-rays are generated in the sample. Therefore, in the second X-ray diffraction apparatus, an X-ray detector having a wavelength selection function of detecting the intensity of diffracted X-rays of a specific wavelength is used as the X-ray detector.

Examples of this type of X-ray detector include, for example, a semiconductor detector or a solid state detector.
etector). Figure 5 shows the general configuration of a semiconductor detector.
Shown in The semiconductor detector 3 shown in FIG.
p-type region 3b, intrinsic region (depletion layer) 3c, n-type region 3
d, and a gold electrode 3e. The intrinsic region (depletion layer) 3c is a region where charge carriers do not exist,
It has good insulation and can apply a strong electric field. X-rays incident on the intrinsic region (depletion layer) 3c generate pairs of electrons and holes. The electrons and holes are swept to the cathode and the anode, respectively, by the applied voltage, and as a result, charge pulses are output (The University of Tokyo Press Physical Science Experiment 15 by Satoshi Kikuta X-ray diffraction and scattering technology (above) P212- 216).

This semiconductor detector has a function of selecting the wavelength of the incident diffracted X-ray and detecting the intensity of the diffracted X-ray at a specific wavelength by generating a number of electron-hole pairs in proportion to the energy of the X-ray photon. It has.

Also in the third X-ray diffractometer according to the present invention, continuous X-rays emitted from an X-ray source are extracted as a parallel X-ray beam by a capillary bundle, and the parallel X-ray beam is sampled without selecting a wavelength. Irradiation. For this reason,
Diffracted X-rays corresponding to each wavelength of the incident X-rays are generated in the sample. Therefore, in the third X-ray diffractometer, a wavelength selecting means is provided between the sample and the X-ray detector to extract the diffracted X-rays of a specific wavelength from the diffracted X-rays generated in the sample and receive the X-rays at the X-ray detector. Let me.

In each of the X-ray diffractometers according to the present invention, a monochromator formed of a spectral crystal can be used as the wavelength selecting means.
In particular, if an asymmetric cut plate crystal monochromator having different incident X-ray widths and output X-ray widths is used, the output X-ray width can be compressed and extracted, and the resolution can be further improved.

The asymmetric cut plate crystal monochromator is obtained by cutting the single crystal 4 obliquely with respect to the crystal lattice plane 4a to form an X-ray diffraction plane 4b as shown in FIG. This is a monochromator configured to take out an output X-ray (diffraction X-ray) R2 asymmetrically with respect to R1. The asymmetry means that the beam width of the outgoing X-ray R2 becomes wider or narrower than the beam width of the incoming X-ray R1. As shown in FIG.
2 is arranged so that the beam width of the incident X-ray R1 is smaller than that of the incident X-ray R1, the outgoing X-ray R2 can be compressed and extracted.

As the X-ray convergence means, for example, a solar slit or a secondary capillary bundle having a smaller cross-sectional area from the X-ray incident end face to the emission end face can be used.

[0029]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 schematically shows an X-ray diffraction apparatus according to a first embodiment of the present invention. This X-ray diffractometer comprises an X-ray tube 7 as an X-ray source having a filament 5 and a rotating target 6, a capillary bundle 1, a monochromator 8 as a wavelength selecting means,
The apparatus includes a solar slit 9 as X-ray focusing means and an X-ray detector 10.

The filament 5 generates heat when energized and emits thermoelectrons, and the thermoelectrons are rotated at high speed by the rotating target 6.
And an X-ray focal point F is formed. From this X-ray focal point F, X-rays containing various wavelengths, that is, continuous X-rays are emitted in a divergent state.

As shown in FIG. 4, for example, the capillary bundle 1 is formed by bending a glass capillary tube 2 having a fine diameter into a parabolic shape, and bundling a large number of them in close contact with each other and assembling them. Divergent X-rays incident on the incident side end face 1a of the capillary bundle 1 are extracted as parallel X-ray beams from the output side end face 1b by the action of the individual glass capillary tubes 2.

By the capillary bundle 1, continuous X-rays are extracted from the emission end face 1b as parallel X-ray beams having a high intensity with almost no attenuation, so that X-rays of each wavelength included in the continuous X-rays are converted to X-rays. It can be used for diffraction measurement.

Returning to FIG. 1, the X-ray diffraction apparatus of this embodiment is provided with two θ-2θ type goniometers (first and second goniometers 11 and 12), each of which is position-independent θ rotation. There are θ turntables 11a and 12a that rotate around the axis ω (so-called θ rotation), and 2θ turntables 11b and 12b that also rotate about the θ rotation axis ω in the same direction as θ rotation at twice the angular velocity. .

The monochromator 8 is mounted on a θ turntable 11a provided in the first goniometer 11, and the X-ray diffraction surface 8a is arranged on the optical path of the parallel X-ray beam extracted from the capillary bundle 1, The configuration is such that the incident angle θ of the parallel X-ray beam with respect to the X-ray diffraction surface 8a can be arbitrarily changed by rotation. By arbitrarily changing the incident angle θ of the parallel X-ray beam with respect to the X-ray diffraction surface 8a in this manner, it is possible to selectively extract diffracted X-rays of various wavelengths having different diffraction angles 2θ.

The monochromator 8 is constituted by, for example, an asymmetric cut plate crystal monochromator 4 as shown in FIG. 6, and is arranged so that the beam width of the outgoing X-ray R2 is smaller than the beam width of the incident X-ray R1. is there. Therefore, the width of the selected parallel X-ray beam having the specific wavelength can be compressed and extracted.

The second goniometer 12 has a 2θ goniometer extending from a 2θ turntable 11b of the first goniometer 11.
It is mounted on the rotating arm 11c. The sample S is placed on the optical path of the parallel X-ray beam of a specific wavelength taken out by the collimator 8 so that the surface of the sample S is placed on the second goniometer 1.
2 is supported by the θ-turntable 12a.

Solar slit 9 and X-ray detector 10
Is a 2θ turntable 12b of the second goniometer 12.
It is mounted on a 2θ rotating arm 12c extending from the arm.
When the incident angle θ of the parallel X-ray beam of a specific wavelength applied to the sample S reaches an angle satisfying the so-called Bragg diffraction condition, diffracted X-rays are generated from the sample S at an angle of 2θ with respect to the incident X-ray. I do. The solar slit 9 has a configuration in which thin metal plates are overlapped at equal intervals, and takes in and converges diffracted X-rays generated in the sample S. Then, this converged diffracted X-ray is incident on the X-ray detector 10 and its X-ray intensity is measured.

FIG. 2 is a diagram showing an X signal according to a second embodiment of the present invention.
1 schematically shows a line diffraction apparatus. In FIG. 2, the same reference numerals are given to the same or corresponding portions as those in FIG. 1 described above, and detailed description of those portions will be omitted. In the second embodiment, the monochromator 8 provided between the capillary bundle 1 and the sample S in the first embodiment is omitted, and a semiconductor detector which is an X-ray detector having a wavelength selection function is used instead. 13 is mounted. In addition, the first goniometer 11 for rotating the monochromator 8 by θ is omitted.

According to the second embodiment, the sample S is irradiated with the parallel X-ray beam (continuous X-ray) extracted from the capillary bundle 1. Therefore, a diffracted X-ray corresponding to each wavelength of the incident X-ray is generated from the sample S. The diffracted X-rays are converged by the solar slit 9 and incident on the semiconductor detector 13, and the intensity of the diffracted X-ray of the selected specific wavelength is measured by the semiconductor detector 13.

FIG. 3 is a view showing a third embodiment of the present invention.
1 schematically shows a line diffraction apparatus. In FIG. 3, the same or corresponding parts as those in FIG. 1 described above are denoted by the same reference numerals, and detailed description of those parts will be omitted. In the third embodiment, the monochromator 11 provided between the capillary bundle 1 and the sample S in the first embodiment is
It is installed in front of the X-ray detector 10. Accordingly, the first goniometer 11 is mounted on a 2θ rotation arm 12c extending from the 2θ rotation table 12b of the second goniometer 12, and the monochromator is mounted on the θ rotation table 11a of the first goniometer 11. 8 is provided. The X-ray detector 10 includes a 2θ rotation arm 11c extending from a 2θ rotation table 11b of the first goniometer 11.
Mounted on top.

According to the third embodiment, the sample S is irradiated with the parallel X-ray beam (continuous X-ray) extracted from the capillary bundle 1. Therefore, a diffracted X-ray corresponding to each wavelength of the incident X-ray is generated from the sample S. This diffracted X-ray is converged by a solar slit 9 and is converted to a monochromator 8.
Incident on. By changing the angle of incidence θ of the diffracted X-rays by the first goniometer 11, the X-ray detector 10 can select a diffracted X-ray having a specific wavelength and receive the X-ray.

The present invention is not limited to the above embodiment. For example, in the third embodiment,
The monochromator 8 can be provided between the sample S and the solar slit 9.

Further, instead of the solar slit 9, a secondary capillary bundle as X-ray convergence means may be provided.
The basic structure of the secondary capillary bundle is the same as that of the capillary bundle 1 shown in FIG. 4. It is formed.

The secondary capillary bundle is the same as the capillary bundle 1
And the emission side end face 1b is reversed. That is, in the secondary capillary bundle, the cross-sectional area decreases from the X-ray incident end face to the emission end face. Therefore, by this secondary capillary bundle, the diffracted X-rays incident on the incident side end face can be converged and extracted from the exit side end face with the function of each glass capillary.

[0045]

As described above, according to the first or third aspect of the present invention, continuous X-rays emitted from an X-ray source are taken into a capillary bundle and taken out as a parallel X-ray beam. Is used to perform X-ray diffraction measurement. Therefore, by simply selecting incident X-rays or diffracted X-rays of an arbitrary wavelength by the wavelength selection means, X-rays of various wavelengths can be obtained.
Line diffraction measurement can be easily performed. According to the second aspect of the present invention, since the X-ray detector has a wavelength selecting function, X-ray diffraction measurement using X-rays of various wavelengths can be easily performed without providing a separate wavelength selecting means.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing an X-ray diffraction apparatus according to a first embodiment of the present invention.

FIG. 2 is a plan view schematically showing an X-ray diffraction apparatus according to a second embodiment of the present invention.

FIG. 3 is a plan view schematically showing an X-ray diffraction apparatus according to a third embodiment of the present invention.

FIG. 4 is a perspective view showing a configuration example of a capillary bundle in a partially broken manner.

FIG. 5 is a diagram schematically illustrating a configuration example of a semiconductor detector.

FIG. 6 is a diagram schematically showing a configuration example of an asymmetric cut plate crystal monochromator.

[Explanation of symbols]

1: Capillary bundle 2: Glass capillary tube 3: Semiconductor detector 4: Asymmetric cut plate crystal monochromator 5: Filament 6: Rotating target 7: X-ray tube 8: Monochromator 9: Solar slit 10: X-ray detector 11 : 1st goniometer 12: 2nd goniometer 13: Semiconductor detector

Claims (8)

[Claims] 1. An X-ray diffractometer for measuring a physical property of a sample by detecting a diffracted X-ray diffracted from the sample when the X-ray is incident on the sample at an incident angle θ. An X-ray source, a capillary bundle for taking out the emitted X-rays as a parallel X-ray beam, wavelength selecting means for receiving the parallel X-ray beam, selecting a parallel X-ray beam of a specific wavelength, and emitting the same, X-ray convergence means for converging diffracted X-rays diffracted from the sample when a parallel X-ray beam of a specific wavelength is incident on the sample at a predetermined angle; and X for detecting the intensity of the converged diffracted X-rays. An X-ray diffraction apparatus comprising: a X-ray detector. 2. An X-ray diffractometer for measuring a physical property of a sample by detecting a diffracted X-ray diffracted from the sample when the X-ray is incident on the sample at an incident angle θ. An X-ray source; a capillary bundle for extracting emitted X-rays as a parallel X-ray beam; and converging diffracted X-rays diffracted from the sample when the parallel X-ray beam is incident on the sample at a predetermined angle. -Ray converging means for receiving the converged diffracted X-ray and diffracting X-rays of a specific wavelength
An X-ray diffractometer comprising: an X-ray detector having a wavelength selection function of detecting the intensity of a ray. 3. An X-ray diffractometer that detects a diffracted X-ray diffracted from a sample when the X-ray is incident on the sample at an incident angle θ, and measures a physical property of the sample. An X-ray source; a capillary bundle for extracting emitted X-rays as a parallel X-ray beam; and converging diffracted X-rays diffracted from the sample when the parallel X-ray beam is incident on the sample at a predetermined angle. -Ray converging means for receiving the diffracted X-rays, and selecting and emitting the diffracted X-rays of a specific wavelength, and detecting the intensity of the converged and wavelength-selected diffracted X-rays of the specific wavelength An X-ray diffractometer comprising: 4. The X-ray diffractometer according to claim 1, wherein the wavelength selector is a monochromator formed of a spectral crystal. 5. The X-ray diffractometer according to claim 4, wherein the monochromator is an asymmetric cut plate crystal monochromator having different incident X-ray widths and output X-ray widths. 6. The X-ray diffraction apparatus according to claim 2, wherein the X-ray detector having the wavelength selection function is a semiconductor detector. 7. The X-ray diffraction apparatus according to claim 1, wherein the capillary bundle has a predetermined curvature, and is cut from an X-ray incident end face to an emission end face. An X-ray diffractometer having a large area. 8. The X-ray diffractometer according to claim 1, wherein the X-ray focusing means has a cross-sectional area from a solar slit or an X-ray incident end face toward an emission end face. An X-ray diffractometer, wherein the secondary capillary bundle becomes smaller.