JPH05149896A - Microdomain x-ray diffraction device - Google Patents

Abstract

PURPOSE:To obtain a microdomain X-ray diffraction device capable of performing X-ray diffraction measurement for a microdomain in a sample in short time and with high resolution. CONSTITUTION:A microdomain X-ray diffraction device radiates a sample 7 by limiting X-ray emitted from an X-ray source to a micro cross section with a collimeter 13 and detects the X-ray diffracted by the sample 7 with an X-ray detector. The X-ray detector includes a cumulative fluorescent material 15.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a small area X-ray diffraction apparatus for obtaining an X-ray diffraction image of a small area of a sample.

[0002]

2. Description of the Related Art It has been widely known that an X-ray diffractometer is used for structural analysis of a sample. In such an X-ray diffraction measurement, a minute area of the sample, for example, a diameter of 1
Some measure X-ray diffraction information in the region of μm to 1 mm. In addition, X-ray analysis may be performed on a small amount of sample of 1 μg to 100 mg. Generally, an X-ray diffractometer for performing these measurements is called a microscopic area X-ray diffractometer.

As a micro-area X-ray diffractometer that has been used conventionally, a collimator limits X-rays to a micro section and irradiates the sample, and the X-ray diffracted by the sample while rotating and rocking the sample is position-sensitive. An apparatus for detecting with an X-ray detector has already been proposed. For example, Japanese Patent Publication 1-46
Japanese Patent Laid-Open No. 822 discloses such a micro area X-ray diffractometer.

[0004]

The conventional micro-area X-ray diffractometer uses a position sensitive X-ray detector as the X-ray detector. As is well known, the width of the X-ray capturing aperture of a position-sensitive X-ray detector is very narrow, and when detecting diffracted X-rays from a sample, only a small part of the Debye ring of diffracted X-rays is detected. It is only observing, so accurate data with high reproducibility cannot be obtained.

In order to solve such a problem, Japanese Patent Publication No. 1
In the apparatus disclosed in Japanese Patent Publication No. 46822, the Debye ring is scanned over a wide range by the position-sensitive X-ray detector by rotating and rocking the sample about two different axes. Generally, as an axis line that is a swing center when swinging a sample, an ω axis line that is an axis line that is orthogonal to the optical axis of the X-ray that enters the sample, and an X-ray line that is orthogonal to the ω axis line. Three orthogonal axis lines are conceivable: a φ axis line that rotationally moves in a plane including the optical axis and a χ axis line that is always orthogonal to both the ω axis line and the φ axis line. In the above conventional device, the substantial measurement region of the sample is expanded by rotating and swinging the sample around at least two axes including at least the above-mentioned χ axis.

However, since the position-sensitive X-ray detector is used in the conventional apparatus, only a small part of the Debye ring, that is, about 2% of the X-ray is detected when measuring the intensity of the diffracted X-ray. There was a problem that it could not be taken into the vessel and the sensitivity was very poor. It is possible to improve the sensitivity by lengthening the measurement time of the diffracted X-rays by the position-sensitive X-ray detector, but this causes another problem that the measurement time becomes extremely long.

Further, since the position sensitive X-ray detector is used, highly reliable measurement results cannot be obtained unless the sample is so-called biaxially swung about at least two axes. In particular, since the χ axis had to be oscillated, there were the following problems. That is, since the χ axis line is an axis line having a relationship of being orthogonal to both the ω axis line and the φ axis line as described above, when the sample is rotationally oscillated around this χ axis line, There is a risk that the incident position will shift and accurate measurement will not be possible.

When the position-sensitive X-ray detector is used, the debye ring D of the diffracted X-rays has an opening P for capturing the X-rays of the position-sensitive X-ray detector as shown in FIG. To cross. In this case, the position-sensitive X-ray detector reads the intensity of X-rays in the area of the width W as one reading unit according to the curvature of the Debye ring. Since the measurement with a certain width is performed in this manner, there is a problem that the resolution of the measurement result is inevitably deteriorated in the measurement using the position-sensitive X-ray detector.

The present invention has been made in view of the above problems in the conventional micro-area X-ray diffractometer, and it is an X-ray having high reliability and high resolution in a short time with respect to a micro area of a sample. It is an object of the present invention to provide a minute area X-ray diffractometer capable of performing diffraction measurement.

[0010]

In order to achieve the above object, a micro-area X-ray diffractometer according to the present invention irradiates a sample with X-rays radiated from an X-ray source by a collimator to limit the micro-section. In the minute area X-ray diffractometer in which the X-ray diffracted by the sample is detected by the X-ray detector, the X-ray detector includes a stimulable phosphor.

In the above structure, the stimulable phosphor is sometimes called a stimulable phosphor and has the following properties. That is, when the stimulable phosphor is irradiated with radiation such as X-rays, energy is accumulated as a latent image in the stimulable phosphor corresponding to the irradiated portion, and the stimulable phosphor is further illuminated by a laser beam or the like. When the exhaustion excitation light is irradiated, the latent image energy becomes light and is emitted to the outside. Examples of such a substance include a phosphor represented by BaFX: Eu (X is a halogen), or JP-A-56-113.
Various phosphors listed as visible or infrared stimulable phosphors in Japanese Patent Laid-Open No. 92 are known.

[0012]

The diffracted X-ray from the sample is detected in a plane by the stimulable phosphor. Since a stimulable phosphor was used, diffraction X
The Debye ring for a line can be measured over a wide range simultaneously. Therefore, it is possible to perform highly reproducible measurement in a short time without swinging the sample, especially around the χ-axis line, without swinging the sample biaxially as in the conventional case.
Further, since the χ-axis swing is unnecessary, the variation of the incident position of the X-ray on the sample is reduced, and highly reliable measurement can be performed. By reading the latent image energy accumulated in the stimulable phosphor corresponding to the Debye ring with a narrow reading width along the Debye ring, a measurement result with extremely high resolution can be obtained. In particular, when the reading is performed with a reading width narrower than the width of the Debye ring, the resolution becomes higher.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows an embodiment of a micro area X-ray diffractometer according to the present invention. This X-ray diffractometer is made with the two axes of the ω axis and the φ axis as reference axes. The ω axis is an axis orthogonal to the optical axis R of the X-rays that enter the sample 7. The φ axis line is an axis line that is orthogonal to the ω axis line, is included in the plane including the X-ray optical axis R, and is orthogonal to the ω axis line.

This X-ray diffractometer is composed of a stationary column 1
A support arm 2 rotatably attached to the support 1 about the ω axis, a Z stage 3 attached to the support arm 2 and movable in parallel along the φ axis, and mounted on the Z stage 3. A rotary table 4 placed on the rotary table 4 and rotatable about the φ axis; and a Y stage 5 mounted on the rotary table 4 and movable in parallel in a direction (YY direction) perpendicular to the φ axis. Then, the Y
It has an X stage 6 which can be translated in the XX 'direction which is perpendicular to the -Y' direction. Sample 7 to be measured
Are mounted on the X stage 6.

The X stage 6 is driven by an X moving motor 8 to move in parallel, and the Y stage 5 is driven by a Y moving motor 9 to move in parallel. The rotary table 4 is driven by the φ-axis motor 10 to rotate about the φ-axis, and the Z stage 3 is driven by the Z-moving motor 11 to move parallel to the φ-axis. The rotation of the turntable 4 causes the sample 7 to rotate in a so-called in-plane direction about the φ axis.
The ω-axis motor 12 fixed to the column 1 rotates the support arm 2 about the ω-axis. When the support arm 2 swings, the sample 7 supported by the support arm 2 swings about the ω axis.

A collimator 13 is arranged between the sample 7 and the X-ray source (not shown). The cross-section of the X-ray incident on the sample is limited to a very small area by the collimator 13, and the limited X-ray is incident on the sample 7. For example, the cross-sectional diameter of X-ray is limited to 1 μm to 1 mm.

A television camera 14 is installed above the sample 7. The television camera 14 projects a magnified image of the surface of the sample 7 on a monitor screen (not shown). A stimulable phosphor 15 as an X-ray detection device is fixedly arranged at a position between the sample 7 and the television camera 14.
The stimulable phosphor 15 is curved in an arc shape around the optical axis R of the incident X-ray.

The operation of the above apparatus will be described below.
First, while observing an image of the sample 7 displayed by the television camera 14, the X stage 6, the Y stage 5, and the Z stage 3 are independently moved in parallel, and the minute measurement points of the sample 7 are measured by the X-ray R. To the incident position of.

After that, the stimulable phosphor 15 is set at the measurement position shown in the figure, and the sample 7 is irradiated with X-rays through the collimator 13. When the sample 7 is irradiated with X-rays, as is well known, X-ray diffraction occurs when the diffraction condition is satisfied between the crystal lattice plane in the sample 7 and the X-rays, and the diffracted X-rays are It is emitted from 7 in various directions. The radiated diffracted X-rays reach the stimulable phosphor 15 and form an energy latent image therein. Reference numeral 15 in FIG. 2 indicates that the stimulable phosphor 15 is developed in a plane. As can be seen from this figure, a plurality of energy latent images corresponding to so-called Debye ring are accumulated in parallel within the stimulable phosphor 15 at intervals.

At the time of the above measurement, the sample 7 is appropriately rotated and oscillated according to the type of measurement. As the mode of the swing, the following modes can be considered. However, it is also possible to adopt any aspect other than those. For example, when measuring a small portion of the sample, the sample 7 is not swung about the ω axis, but is swung in the plane about the φ axis. Also, when using a uniaxially oriented substance such as a vapor deposition film or a fiber material as a sample, do not rock it around the φ axis line,
Swing around the ω axis. Further, when the transmission method measurement is performed on the single crystal sample, the sample is rocked around both the φ axis and the ω axis. Further, when the powder sample is packed in a capillary glass rod and the measurement by the transmission method is performed, the powder sample is rotated and rocked about either the φ axis or the ω axis.

After the above processing is completed, the stimulable phosphor 1
5 is removed from the X-ray diffractometer and mounted on a reader (not shown). Then, the energy latent image in the stimulable phosphor is read by the reading device. A known device can be used for this reading device, so a detailed description thereof will be omitted. Basically, a stimulable phosphor carrying an energy latent image is irradiated with laser light, and at that time, the stimulable phosphor emits light. The generated excitation light is extracted as an electric signal by the photoelectric conversion device.

The above-mentioned reading device reads the energy intensity accumulated at each coordinate position of the stimulable phosphor, and if the read X-ray intensity signal is plotted on a graph, as shown in FIG. , X-ray intensity on the vertical axis,
A so-called X-ray diffraction pattern is obtained on a coordinate system with the X-ray diffraction angle on the horizontal axis. Based on this diffraction pattern, sample 7
Can be observed. The reading width of the stimulable phosphor by the reader is preferably narrower than the line width of the Debye ring as an energy latent image accumulated in the stimulable phosphor. By doing so, the resolution in the obtained X-ray diffraction pattern can be improved.

The resolution of the measurement data can be adjusted by adjusting the curvature of the curved shape of the stimulable phosphor 15. For example, it is convenient to prepare a plurality of cassettes for holding stimulable phosphors having different curvatures and use a desired cassette according to the desired resolution.

When precise measurement is required,
The standard data as shown in Fig. 2 is collected in advance for the reference substance whose lattice constant is known, and then the unknown sample is measured to obtain the measurement data as shown in Fig. 2 as well. It is possible to employ a method in which the crystal structure of an unknown sample is analyzed by comparing with the above standard data.

Since the stimulable phosphor 15 is used as the X-ray detection device in the above-mentioned micro-region X-ray diffractometer, the sample 7 is used.
Diffracted X-rays can be obtained in a wide range simultaneously and in a short time. Further, in the conventional apparatus using the position sensitive X-ray detector, the sample is not swung about at least two axes including the χ axis which is an axis orthogonal to both the ω axis and the φ axis. And accurate measurement results with high reproducibility were not obtained. On the other hand, with the apparatus according to the above-described embodiment, highly reproducible measurement results can be obtained without swinging the χ axis.

As shown in FIG. 1, the stimulable phosphor 1
If a flat auxiliary stimulable phosphor 25 is provided on the back surface of No. 5, X-ray diffraction information on the low angle side can be obtained. Code 16
Is a beam stopper. Further, if the auxiliary stimulable phosphor 25 is installed in front of the stimulable phosphor 15 indicated by the arrow A, the X-ray diffraction information on the high angle side can be obtained.

FIG. 3 shows a second embodiment of the minute area X-ray diffractometer according to the present invention. The difference of this embodiment from the previous embodiment shown in FIG. 1 is that the stimulable phosphor 15 is curved in a conical shape with the optical axis R of the incident X-ray as the center line. By doing so, it becomes possible to obtain the diffracted X-ray information on the low-angle side or the high-angle side by using one stimulable phosphor.

FIG. 4 shows a third embodiment of the minute area X-ray diffractometer according to the present invention. This embodiment is different from the first embodiment shown in FIG. 1 in that the stimulable phosphor 1
This is a point in which the bending direction of Sample No. 5 with respect to Sample 7 was changed. That is, in this embodiment, not the optical axis R of the incident X-ray but ω
The stimulable phosphor 15 is curved in an arc shape around the axis. In addition, FIG. 5 shows the energy latent image corresponding to the Debye ring of the diffracted X-rays, which is accumulated in the stimulable phosphor 15 by the X-ray diffractometer, for convenience of viewing. The apparatus of FIG. 1 and the apparatus of FIG. 4 can be arbitrarily selected and used according to the situation of the place where the microscopic region X-ray diffraction apparatus is installed.

The energy latent image accumulated in the stimulable phosphor 15 in FIG. 5 draws a curve as shown.
Therefore, when the stimulable phosphor 15 is read by scanning in parallel with the E direction by the reading device, the energy latent image on one curve is read as the information of the same diffraction angle (2θ). The data read by parallel scanning is processed by a computer, and the diffraction angle (2
It is necessary to compensate the position information for θ).

Although the present invention has been described based on the preferred embodiments, the present invention is not limited to the embodiments. For example, the stimulable phosphor 15 may be arranged in a spherical shape centered on the sample 7 in addition to the arc-shaped curved surface (FIGS. 1 and 4) or the conical curved surface (FIG. 3). .. By doing so, it becomes possible to read the diffracted X-rays from the sample 7 in an extremely wide range, and therefore, it becomes possible to perform measurement with extremely high resolution.

Further, in each of the illustrated embodiments, the stimulable phosphor 15 is arranged on the upper surface side of the sample 7, but instead of this, the stimulable phosphor 15 may be arranged on the side surface side of the sample 7. is there. By adopting such a configuration of the side surface arrangement, since a wide space is secured above the sample, an environmental device such as a heating device for keeping the sample at a high temperature can be easily attached.

[0032]

According to the present invention, diffracted X-rays can be read over a wide range by the stimulable phosphor, so that measurement data with high reproducibility and resolution can be obtained in a short time. Further, it is not necessary to swing the sample biaxially in order to obtain measurement data with sufficient accuracy. In particular, it is not necessary to swing the χ axis. Since one swinging mechanism can be omitted in this manner, the structure of the sample holding mechanism can be simplified, and therefore, the positional accuracy of the sample to be held can be maintained at extremely high accuracy. In particular, the χ-axis is an axis orthogonal to both the ω-axis and the φ-axis, and it is not necessary to oscillate around the χ-axis, which means that the incident X-ray is always applied to a fixed position on the sample. It is extremely convenient for.

[Brief description of drawings]

FIG. 1 is a perspective view showing a first embodiment of a microscopic area X-ray diffractometer according to the present invention.

FIG. 2 is a diagram showing an outline of an example of measurement data obtained by the above apparatus.

FIG. 3 is a perspective view showing a second embodiment of the microscopic area X-ray diffractometer according to the present invention.

FIG. 4 is a perspective view showing a third embodiment of the minute area X-ray diffraction apparatus according to the present invention.

5 is a diagram schematically showing an example of measurement data obtained by the embodiment shown in FIG.

FIG. 6 is a schematic diagram showing a measurement state when a position-sensitive X-ray detector that has been conventionally used is used.

[Explanation of symbols]

 7 Sample 13 Collimator 15 Storage phosphor

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Masataka Sakata 3-9-12 Matsubara-cho, Akishima-shi, Tokyo Rigaku Denki Co., Ltd. Haijima factory (72) Osamu Hirashima 3-9-12 Matsubara-cho, Akishima-shi, Tokyo Rigaku-denki Haijima Factory Co., Ltd.

Claims (7)

[Claims] 1. A small area X-ray in which X-rays emitted from an X-ray source are limited to a minute cross section by a collimator to irradiate a sample, and X-rays diffracted by the sample are detected by an X-ray detector. A diffractometer, wherein the X-ray detector includes a stimulable phosphor, and a minute area X-ray diffractometer. 2. The stimulable phosphor is X incident on a sample.
The minute area X-ray diffractometer according to claim 1, wherein the minute area X-ray diffractometer is arranged so as to be curved in an arc shape around the optical axis of the line. 3. A flat auxiliary stimulable phosphor at a front surface or a back position as viewed in the X-ray traveling direction with respect to the curvilinearly arranged stimulable phosphor, at a right angle to the X-ray traveling direction. The minute area X-ray diffractometer according to claim 2, further comprising: 4. The stimulable phosphor is X incident on a sample.
The minute area X-ray diffractometer according to claim 1, wherein the minute area X-ray diffractometer is arranged so as to be curved in a conical shape having an optical axis of the line as a center line. 5. The stimulable phosphor is X incident on a sample.
The curved line is arranged around an ω axis extending in a direction perpendicular to the optical axis of the line in an arc shape.
The minute area X-ray diffractometer described. 6. The micro area X-ray diffractometer according to claim 2, wherein the curving curvature of the stimulable phosphor is adjustable. 7. The micro-region X-ray diffraction apparatus according to claim 1, wherein the stimulable phosphor is arranged in a spherical shape centered on the sample.