JP2550382B2 - X-ray diffractometer - Google Patents

Description

TECHNICAL FIELD The present invention relates to an X-ray diffractometer which enables measurement by various X-ray diffraction methods with a relatively simple structure.

[Prior Art] Crystal information of a sample is obtained by measuring the diffraction angle of a diffracted X-ray that is diffracted from the sample when the crystalline sample is irradiated with X-rays. The most commonly known conventional line diffractometer is a so-called X-ray diffractometer (diffractomete).
r) (for example, Seiki Tanaka et al., "Machine Analysis", Showa 4)
(September 2006, published by Shokabo, p152).

In this X-ray diffractometer, a crystalline powder sample is irradiated with monochromatic dispersed X-rays from a certain direction while rotating the sample at an angular velocity θ, and at the same time, an X-ray detector for detecting diffracted X-rays from the sample is used. The sample is rotated about the rotation axis of the sample at an angular velocity of 2θ in synchronization with the rotation of the sample.

In the measurement by this device, in short, among the countless crystals contained in the sample, attention is focused on the crystal whose angle formed by the lattice plane with respect to the direction of the irradiation X-ray is θ, and this crystal satisfies the Bragg diffraction condition. The lattice spacing is determined by determining the value of.

[Problems to be Solved by the Invention] By the way, in the measurement by the above-mentioned X-ray diffractometer, the measurement is performed by changing the sample with respect to the direction of the irradiation X-rays.
It is premised that the innumerable crystals contained in the sample are oriented in random directions and the total number of crystals oriented in an arbitrary direction is almost the same. That is, it is premised that the sample is uniform, and for example, the number of crystals facing a specific direction is larger than others (such a state has orientation). If there is, the assumption is broken and a measurement error occurs.

However, depending on the purpose of measurement, it may not be possible to apply the desired treatment to the sample, and for example, it may be necessary to perform measurement in the state in which it has the above-described orientation.
Conventionally, in such a case, the measurement should be prepared by measuring the error, or if such an error is not allowed, a special device is newly designed and manufactured separately from the diffractometer. It had to be a dedicated device.

In addition, the conventional X-ray diffractometer can only measure the diffracted X-rays that are normally reflected on the front surface of the sample (measurement by the so-called reflection method) because of the structural restrictions, and the diffracted X-rays that reach the back surface of the sample. Could not be measured (measurement by the so-called transmission method).

As described above, the conventional X-ray diffractometer has a sufficient function for a certain purpose, but cannot be applied to various other measurement purposes.

The object of the present invention is to solve such technical problems.
It is to provide a line diffraction device.

[Means for Solving the Problem] The present invention is based on a mechanism similar to the mechanism of a goniometer, which is a rotation mechanism of θ · 2θ in a conventional X-ray diffractometer, and has a portion corresponding to the 2θ rotating portion of the goniometer. The arm similar to the goniometer is provided with an arm extending outward from the center of rotation to hold an X-ray detector movably along the arm, and irradiation of a mechanism similar to the goniometer is provided. The distance to the X-ray source can be changed, so that the X-ray diffractometer can be used as a conventional X-ray diffractometer with a relatively simple structure and can be used for various other measurement purposes. A line diffractometer is used. Specifically, an X-ray source for generating X-rays for irradiating a sample and an axis provided in a plane including the X-ray incident surface of the sample for holding the sample are provided. at the center A sample rotation base rotatably supported, an arm portion rotatably supported around the rotation axis of the sample rotation base and extending outward from the rotation center, and held by the arm portion. In an X-ray diffraction apparatus having an X-ray detector for detecting diffracted X-rays from the sample, the rotating sample stage and an arm portion holding the X-ray detector are placed, and these and the A movable table configured to be movable is provided so that the distance between the X-ray source and the X-ray source can be changed, and the arm has a fixed relationship with the rotation of the sample rotary table and / or the arm. In order to change the distance between the sample and the X-detector, a moving table configured so that the X-ray detector is placed and the arm can be moved in the longitudinal direction is used. It has a configuration characterized by being provided.

[Operation] In the above-mentioned configuration, the X-ray detector is fixed at a predetermined position of the arm portion, and the sample rotary table and the arm portion are set to θ, 2
The conventional X-ray diffractometer can be used by rotating in the relationship of θ.

Further, the sample rotary table is fixed, the sample held on the sample rotary table is irradiated with focused X-rays, and the X-ray detector supported by the arm section is rotated while rotating the arm section. The position where the diffracted X-rays from the sample are always focused by the detector being moved in synchronization with the rotation of the arm on the arm (the curve connecting these positions forms a so-called Roland circle). The X-ray diffraction measurement by the concentration method can be performed without changing the incident angle of the X-ray with respect to the sample.

In this case, the incident angle of the X-ray on the sample can be set to an arbitrary angle by adjusting the rotation angle of the sample rotating table. Therefore, the incident angle can be variously changed according to the property of the sample and the same as the above. It is extremely easy to make a measurement.

Therefore, even for a sample having a strong orientation that cannot be measured by a conventional X-ray diffractometer, the X
The accurate crystal information can be obtained by the line diffraction method.

Further, by moving the movable table to change the distance to the X-ray source, the positional relationship between the focusing point of the X-ray source and the X-ray incident point of the sample can be arbitrarily changed, so that the arm portion rotates. It is possible to establish a positional relationship such that the arm portion does not collide with the X-ray source at this time, whereby measurement by a so-called reflection method for measuring diffracted X-rays diffracted on the front side of the sample, or sample It is possible to freely perform desired measurement such as measurement by a so-called transmission method for measuring diffracted X-rays diffracted on the back side of the.

[Embodiment] FIG. 1 is a plan view showing the configuration of an X-ray diffraction apparatus according to an embodiment of the present invention.

In the figure, reference numeral 1 is a movable base, and the movable base 1 is slidable on two rails 2, 3 laid on a base (not shown) on the rails 2, 3 in the direction of arrow a in the figure. Supported by.

Further, the movable table 1 has a substantially circular shape in a plan view and is rotatably provided at a substantially central portion of the movable table 1 about a rotation axis O that stands upright at a right angle to the movable table 1. And a fixed portion 5 coaxially provided with the sample rotary table 4 so as to surround the outer periphery of the sample rotary table 4 and having a substantially annular shape in plan view,
The rotary unit is provided coaxially with the sample rotary base 1 and the fixed unit 5 so as to surround the outer circumference of the fixed unit 5, and is rotatably provided around the rotation axis O and has a substantially annular shape in a plan view. And 6 are provided.

An arm portion 7 is formed on the rotating portion 6 by extending a part of an outer peripheral portion of the rotating portion 6 along a straight line extending outward from the rotation axis O.

A rail 8 is laid along the longitudinal direction of the arm portion 7, and a moving base 9 is attached to the rail 8 so as to be slidable on the rail 8 as indicated by an arrow b in the figure. A slit 10 and an X-ray detector 11 for detecting X-rays passing through the slit 10 are fixed to the moving table 9.

In this case, although not shown in the drawings, the rotary sample table 4 and the rotary section 6, or the rotary table 6 and the rotary section 6 are provided at appropriate portions of the movable table 1 and the movable table 9 of the arm portion 7 in accordance with a command from an external controller. A drive mechanism including a well-known drive source such as a pulse motor for independently rotating or linearly moving the moving base 9 is incorporated.

Further, a curved monochromator 12 is provided at a portion located further left from the left end portion of the rails 2 and 3 in the figure,
An X-ray 13 is provided at a portion located below the curved monochromator 12 in the figure.

In the above-mentioned configuration, the moving table 9 to which the X-ray detector 11 is fixed is fixed to a predetermined position of the arm portion 7, and the sample rotating table 4 and the rotating portion 6 (that is, the arm portion 7) are θ. Two
The conventional X-ray diffractometer can be used by rotating in the relationship of θ.

Further, while fixing the sample rotary table 4 and irradiating the sample 14 held on the sample rotary table 4 with focused X-rays x through the X-ray source 13 and the curved monochromator 12, the arm part 7 is shown in the figure. By rotating the X-ray detector 11 supported by the arm portion 7 while rotating as shown by an arrow c in synchronization with the rotation of the arm portion 7 in a constant relationship, the X-ray detector 11 is moved on the arm portion 7. Detector 11 is always diffracted X-rays y1, y from the sample 14
2 can be made to pass through the positions p1 and p2 at which they are focused (the curve connecting these positions forms the so-called Roland circle r1), which enables the concentration method without changing the incident angle of X-rays on the sample. X-ray diffraction measurement by

In this case, the incident angle of the X-ray with respect to the sample 14 can be set to an arbitrary angle by adjusting the rotation angle of the sample rotating table 4, so that the incident angle can be variously changed according to the property of the sample. It is extremely easy to perform the same measurement as.

Therefore, even for a sample having a strong orientation that cannot be measured by a conventional X-ray diffractometer, the X
The accurate crystal information can be obtained by the line diffraction method.

Further, by moving the movable table 4 to change the distance to the X-ray source 13, the positional relationship between the X-ray focusing points (p1, p2) and the X-ray incident point of the sample can be arbitrarily changed. The positional relationship can be such that the arm portion 7 does not collide with the curved monochromator 12 and the X-ray source 13 when the arm portion 7 rotates. It is possible to freely perform a desired measurement such as a so-called reflection method for measuring X-rays, or a so-called transmission method for measuring diffracted X-rays diffracted on the back side of the sample.

2 and 3 are diagrams showing the locus of the X-ray detector 11 in each of the above-mentioned measurement methods, and FIG.
By the transmission method (the diagram located on the left side of the figure) and the reflection method (the diagram located on the right side of the figure) in the case where is arranged so that its incident surface is substantially orthogonal to the irradiation X-ray x. FIG. 3 is a diagram in the case where the sample 14 is arranged so that its incident surface with respect to the irradiation X-ray x is different from that in the case of FIG. In FIGS. 2 and 3, r2, r3, and r4 represent Roland circles in each case.

EFFECTS OF THE INVENTION As described in detail above, the present invention is based on a mechanism similar to that of a goniometer, which is a rotation mechanism of θ · 2θ in a conventional X-ray diffractometer, and corresponds to the 2θ rotating portion of the goniometer. A portion similar to the goniometer is provided with an arm portion outward from the center of rotation of a mechanism similar to the goniometer and holds an X-ray detector movably along the arm portion. The distance to the irradiation X-ray source of the mechanism can be changed, so that the X-ray diffractometer can be used as a conventional X-ray diffractometer with a relatively simple structure and can be used for various other measurement purposes. This is an X-ray diffractometer capable of

[Brief description of drawings]

FIG. 1 is a plan view showing the structure of an X-ray diffraction apparatus according to an embodiment of the present invention, and FIGS. 2 and 3 are X-ray detections when various measurements are performed by the apparatus shown in FIG. 3 is a diagram showing the trajectory of the container 11. FIG. 1 ... Movable table, 4 ... Rotating sample table, 7 ... Arm section, 11 ... X-ray detector, 12, 13 ... Curved monochromator and X-ray source constituting X-ray irradiation means.

Claims (1)

(57) [Claims] 1. An X-ray source for generating X-rays for irradiating a sample,
A sample rotary table that holds the sample and is rotatably supported about an axis provided in a plane including an X-ray incident surface of the sample, and rotatably supported about a rotation axis of the sample rotary table. And an X-ray diffractometer having an arm extending outward from the center of rotation and an X-ray detector held by the arm for detecting diffracted X-rays from the sample, A movable table configured so as to be movable so that the rotating sample table and the arm portion holding the X-ray detector are placed and the distance between these and the X-ray source can be changed. The X-ray is provided on the arm so that the distance between the sample and the X-detector can be changed in a fixed relationship with the rotation of the sample turntable and / or the arm. A movement configured so that the detector is placed and the arm is movable in the longitudinal direction. X-ray diffractometer, wherein a is provided.