JPH09229880A - X-ray diffraction apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an X-ray diffraction apparatus with a rotary sample stage which functions both as a rotary powder sample stage and a fiber sample stage, thereby saving the adjustment labor. SOLUTION: An axial part 4 of a rotary sample stage 1 is supported by a bearing 6 to be rotatable to a bracket 13. A sample holder-holding part 5 is a couplet to a front end of the axial part 4, and a sample holder 17 is detachably fitted to the holding part 5. A pulley 7 is mounted to the axial part 4, which is coupled by a stepping motor 11 and a timing belt 12 thereby to rotate the axial part 4. A collimator 10 is built in the axial part 4, making it possible to project X rays also from a rear face of a sample. A disk 8 and a sensor 9 are set at a rear end of the axial part 4 to detect a rotational origin. A projection 3 is fitted in an engaging hole formed at the center of a goniometer, so that a center axis of the projection, virtually a surface of the sample held by the sample holder 17 agrees with a rotary shaft 16 of the goniometer.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray diffractometer equipped with a rotating sample table on a goniometer for holding a sample rotatably within its sample surface.

[0002]

2. Description of the Related Art An X-ray diffractometer irradiates an X-ray from an X-ray source onto a sample placed at the center of the θ axis of a goniometer, and an X-ray detector fixed to the 2θ axis of the goniometer is placed around the sample. While rotating, measure the intensity of the diffracted X-rays emitted from the sample and qualitatively determine the sample based on the detected angle and the measured intensity.
This is a device for quantitative analysis.

When analyzing a powdery sample with this X-ray diffractometer, the powder sample is filled in a sample filling hole formed in a plate-shaped sample holder and placed on a sample table placed at the center of the θ axis of a goniometer. After mounting, the X-ray detector is rotated around the sample and the diffraction pattern is measured. However, in a powder sample with insufficient mixing or large individual crystal grains, the number of crystal grains that contribute to the generation of diffraction lines in one direction decreases and the diffracted X-ray intensity decreases. There is a problem of including an error. In such a case, a rotating powder sample stage is used for the purpose of rotating the sample in the sample plane at a relatively high speed and increasing the number of crystal grains contributing to diffraction.

On the other hand, in the case of analyzing an oriented sample or a fibrous sample, in the case of a fixed type sample table, the sample is incident depending on how the sample is packed in the sample holder and how the sample holder is mounted on the sample table. Since the orientation of the sample changes with respect to the detection directions of the X-rays and the diffracted X-rays, the diffracted X-rays that should originally be detected may not be clearly obtained. In such a case, the sample is rotated in the plane of the sample in order to change the direction of the sample with respect to the detection directions of the incident X-rays and the diffracted X-rays so that the diffracted X-rays can be clearly detected. A fiber sample stand that changes its orientation by being used is used.
Normally, in this fiber sample stand, X from the X-ray tube from the back of the sample
The sample is irradiated with a ray and the diffracted X-ray transmitted through the sample is detected. At this time, a collimator that controls the direction and width of the irradiation X-ray is installed near the X-ray emission port of the X-ray tube, and the X-ray that is narrowed down is irradiated in advance on the optical axis so that the thin fibrous sample is irradiated. It is necessary to make adjustments.

As described above, the measurement method is different between the powder sample and the fibrous sample, and accordingly, the sample table used has a different type. That is,
In the measurement of a powder sample, a goniometer is usually driven in conjunction with θ-2θ to measure a diffracted X-ray in a direction reflected from the sample surface. On the other hand, in the measurement of a fibrous sample, X-rays are radiated fixedly from the back surface of the sample without performing θ rotation for rotating the sample surface, and 2θ rotation for rotating only the detector around the sample is performed. The diffracted X-ray transmitted through the sample is detected. Conventionally, the rotating powder sample table used for powder samples is designed only for the measurement of the reflection method, and a motor for rotation is arranged behind the sample, so the sample for performing the transmission method is used. It could not be used as a stand. Therefore, the rotating powder sample stand and the fiber sample stand are conventionally prepared as separate accessories of the X-ray diffractometer, and they are attached to the goniometer according to the sample to be analyzed and used for analysis after adjusting the optical axis. Was.

[0006]

As described above, the conventional X-ray diffractometer is provided with the rotating powder sample stage and the fiber sample stage separately. Since a sample is often analyzed, a rotating powder sample stage is usually mounted on the goniometer. Therefore, when a fibrous sample or the like is analyzed, it is necessary to replace the sample table with a dedicated fiber sample table each time, which requires a lot of trouble. Also, when the sample table is replaced with a fiber sample table, it is necessary to adjust the optical axis of the collimator for narrowing the X-ray from the tube each time. These tasks were very troublesome.

The present invention has been made in view of the above circumstances, and is provided with a rotating sample stage which has the functions of a rotating powder sample stage and a fiber sample stage, and which saves the trouble of adjusting the optical axis. Another object of the present invention is to provide an X-ray diffractometer.

[0008]

In order to solve the above-mentioned problems, the present invention provides an X-ray diffractometer equipped with a rotating sample stage having a mechanism for rotating a sample in a sample plane, and a rotating shaft for rotating the sample. A space through which irradiation X-rays from the back can pass is provided inside, and a collimator is built into this space.

The X-ray diffractometer of the present invention is constructed as described above, has a mechanism for rotating the sample in the sample plane, and has a space through which the irradiated X-rays can pass inside the rotating shaft for rotating the sample. Since a collimator is built in this space, the powder sample can be irradiated with X-rays from the surface of the sample to measure the diffracted X-rays by the reflection method, and the fibrous sample can be measured from the back of the sample. It can be measured by a transmission method by irradiating X-rays. Further, since the collimator is built in in a pre-adjusted state, it is not necessary to adjust the optical axis of the collimator, which was required in the past.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a vertical cross-sectional view showing a rotating sample stage which is a main part of an X-ray diffraction apparatus of the present invention.

The rotating sample table 1 has a shaft 4 rotatably supported by a bearing 6 with respect to a bracket 13. A sample holder holder 5 is connected to the tip of the shaft portion 4, and a sample holder 17 is detachably attached to the sample holder holder 5. Further, a pulley 7 is attached to the shaft portion 4, and the pulley 7 is connected to the stepping motor 11 by a timing belt 12. By driving the stepping motor 11, the shaft portion 4 is rotated. The sample holder is continuously rotated by continuously driving the stepping motor 11, and when the stepping motor 11 is driven by a certain angle, the sample holder is also tilted by a certain angle according to the angle, and the stepping motor 11 is held. Held in that position by torque. A disk 8 having a slit for transmitting light is attached to the rear end of the shaft portion 4, and a sensor 9 including an LED and a phototransistor detects this slit and serves as an origin of rotation.

These components are fixed on the bottom plate 2 having the protrusion 3 at the center through the bracket 13,
The positional relationship is such that the central axis of the protrusion 3 and the surface of the sample holder 17 coincide with each other. The projection 3 attached to the bottom plate 2 is fitted into a fitting hole provided at the center of a goniometer (not shown), and the central axis of this projection and further the surface of the sample held by the sample holder 17 are attached to the goniometer. It becomes to coincide with the rotating shaft 16 of.

At the center of the shaft portion 4, a through hole is formed penetrating in the axial direction of the shaft portion 4 to provide a space through which the irradiation X-rays can pass, and a collimator 10 is built in. A member having a small hole fitted in the rear end and the front end of the shaft portion 4 functions as a collimator, and limits the X-ray 14 generated by the tube to irradiate the central portion of the sample. At this time, the optical axis 15 through which the X-rays coincide with the central axis of the shaft portion 4, that is, the rotation axis.

As the sample holder 17, as shown in FIG. 2, a sample holder having a shape suitable for the kind of sample such as a powder sample and a fibrous sample is used. FIG. 2A shows a holder for a powder sample. A circular or quadrangular hole is formed in the center of a plate having a predetermined size and thickness, and the powder sample 21 is filled in the hole. The sample may be filled on a flat glass plate or the like so that the surface of the powder sample matches the surface of the sample holder plate. FIG. 2 (b) shows a holder for a fibrous sample, in which both ends of the fibrous sample are sandwiched by sandwiching plates provided above and below the central space of a plate having a predetermined size and thickness. The fiber sample is fixed, and the fibrous sample is stretched by pulling the upper end by a screw mechanism. Each of these sample holders can be mounted on the sample holder holding portion 5 of FIG. 1, and in this state, the sample surface is made to coincide with the goniometer rotation shaft 16.

Next, a method for measuring diffracted X-rays by the reflection method and the transmission method according to the type of sample using the X-ray diffractometer of the present invention will be described. 3 and 4, the X-ray tube 31 is an X-ray generation source and generates primary X-rays for irradiating the sample. The goniometer 34 is of a type in which the θ axis and the 2θ axis can be driven independently, the rotating sample stage 33 is fixed to the center of the goniometer 34, that is, the θ axis, and can freely rotate by θ, and the detector 35 is a goniometer. It is fixed to the 2θ axis and can rotate around the sample. The surface of the sample holder attached to the rotating sample table 33 is positioned at the rotation center of the goniometer, and the primary X-rays from the X-ray tube are irradiated toward the sample at the rotation center. In that state, while rotating the detector 35 (2θ axis), qualitative and quantitative analysis of the sample is performed by measuring the diffraction angle and intensity of the diffracted X-rays emitted in various directions by the sample. You can 3 and 4 exemplify a so-called vertical type goniometer in which the rotation surface of the goniometer is arranged so as to stand in the vertical direction.
It goes without saying that a horizontal goniometer arranged so that the surface of rotation is horizontal may be used.

FIG. 3 is a view for explaining the arrangement of the reflection method used for measuring a powder sample. The powder sample is filled in the powder sample holder as shown in FIG. 2A, and the sample holder is mounted on the rotary sample table 33 as described in FIG. Then, the rotating sample table 33 is rotated by the θ axis of the goniometer to such an angle that the surface of the sample is irradiated with the X-rays 36, and the primary X-rays 36 from the X-ray tube 31 are irradiated from the surface direction of the sample. The detector 35 detects the diffracted X-rays emitted in the direction reflected from the surface. During measurement of diffracted X-rays, the rotary sample stage 33 and the detector 35 are rotationally scanned around the central axis of the goniometer as indicated by arrows A and B, respectively, in a so-called θ-2θ interlocking relationship. At the time of this measurement, the powder sample holder 37 is rotated at a relatively high speed in the sample plane by the sample rotating mechanism provided on the rotating sample table 33 if necessary because of the coarse particles of the sample. By doing this X
The number of particles contributing to the diffraction of the line is increased, and a smooth diffraction pattern can be obtained. It is preferable that the rotation speed in the sample plane is as high as possible, but some rotation speeds may be selected according to the scanning speed of the detector 35.

On the other hand, FIG. 4 is a view for explaining the arrangement of the transmission method used in the case of a fiber sample. In this arrangement, the collimator 39 built in the rotary sample table 33 is the X-ray tube X-axis.
The scattering prevention slit 32 is fixed so as to face the line generation point.
The X-ray 36 that has passed through the collimator 39 and the collimator 39 is irradiated from behind the fibrous sample attached to the fiber sample holder 38,
The X-ray diffracted by the sample is detected by the detector 35. When measuring diffracted X-rays, the θ axis of the goniometer is not moved (that is, the rotary sample stage 33 is fixed as described above), and the detector 35 on the 2θ axis is centered on the central axis of the goniometer as indicated by arrow B. Is rotated and scanned. At the time of this measurement, if necessary, the fiber sample holder 38 is rotated to a required angle in the sample plane by the rotating mechanism provided on the rotating sample table 33, and fixed at that position.

When measuring a fiber sample as shown in FIG. 4, it is necessary to use a collimator to narrow down the irradiated X-rays so that the irradiated X-rays are exactly irradiated onto the thin fiber sample. In the rotating sample table, the collimator is built in the rotating sample table and the axis adjustment is completed in advance, so that it is not necessary to newly adjust the collimator when measuring the fiber sample.

[0019]

The rotating sample table provided in the X-ray diffraction apparatus of the present invention has a mechanism for rotating the sample in the sample plane, and opens a space behind the sample through which the irradiated X-rays can pass. Since the collimator is built in this space, it is possible to irradiate the powder sample with X-rays from the surface of the sample and measure the diffracted X-rays by the reflection method. It can be measured by a transmission method by irradiating X-rays. Therefore,
Whether the sample is a powder sample or a fibrous sample, it is not necessary to replace the sample table, and it is no longer necessary to set the origin of the θ angle of the goniometer, which is inevitable when the sample table is replaced. Furthermore, since the collimator is built in in a pre-adjusted state, the optical axis adjustment of the collimator, which has been conventionally required when measuring a fibrous sample, becomes unnecessary. That is, according to the present invention, it is possible to provide an X-ray diffractometer having both the functions of the rotating powder sample stage and the fiber sample stage by providing one rotating sample stage, and there is a remarkable effect that it takes almost no adjustment work. .

[Brief description of drawings]

FIG. 1 is an embodiment of a rotating sample stage which is a main part of an X-ray diffraction apparatus of the present invention.

FIG. 2 is an example of a sample holder used for the rotary sample table of the main part of the present invention.

FIG. 3 shows a diffraction X-ray by a reflection method using the X-ray diffractometer of the present invention.
It is an arrangement for measuring a line.

FIG. 4 shows a diffraction X-ray by a transmission method using the X-ray diffractometer of the present invention.
It is an arrangement for measuring a line.

[Explanation of symbols]

1 ... Rotating sample table, 2 ... Bottom plate, 3 ... Protrusion, 4 ... Shaft part, 5 ...
Sample holder holding part, 6 ... Bearing, 7 ... Pulley, 8
... disk, 9 ... sensor, 10 ... collimator, 11 ... stepping motor, 12 ... timing belt, 13 ... bracket, 14 ... X-ray, 15 ... optical axis, 16 ... goniometer rotation axis, 17 ... sample holder, 31 ... X-ray Tube, 32 ... X-ray scattering prevention slit, 33 ... Rotating sample stand, 34 ... Goniometer, 35 ... Detector, 36 ... X-ray, 37 ... Powder sample holder, 38 ... Fiber sample holder, 39 ... Collimator

Claims (1)

[Claims] 1. An X-ray diffraction apparatus equipped with a rotating sample stage having a mechanism for rotating a sample in a sample plane, wherein a space through which irradiation X-rays from behind can pass is provided inside a rotating shaft for rotating the sample. An X-ray diffractometer characterized in that a collimator is incorporated in this space.