JP3221619B2 - X-ray diffractometer - Google Patents

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 apparatus, and more particularly to an automatic adjustment of a slit width of a divergent slit or the like provided in an X-ray diffraction apparatus.

[0002]

2. Description of the Related Art An X-ray diffractometer such as a diffractometer using a line focus as an X-ray source is disposed between a sample and an X-ray source in order to limit the divergence angle of incident X-rays. Divergence slit and diffraction X
A receiving slit disposed at the focus position of the ray (that is, on the focal circle), and between the X-ray counter and the sample to prevent the scattered X-ray from entering the X-ray detector. Many types of slits, such as scatter slits, are used.

[0003] Each of these slits prevents the intensity of diffracted X-rays from decreasing due to a shortage of the X-ray irradiation area on the sample, etc.
Alternatively, in order to prevent unnecessary scattered X-rays from entering the counter tube, it is necessary to adjust the slit width in accordance with the θ rotation of the sample.

Therefore, in the past, various slit plates having different slit widths were prepared for each of the divergent slit, the light receiving slit, and the scattering slit, and the user of the apparatus was required to change the value of θ in a timely manner. The response was to replace the slit plate itself by hand.

[0005] However, such a measure has a problem that the measurement work is interrupted every time the slit plate is replaced, and the replacement work itself becomes a burden on the apparatus user, and the efficiency of the measurement work is significantly reduced. there were.

In addition, the slit width cannot be continuously adjusted according to the change in θ, and as a result, it is impossible to measure the improvement in measurement accuracy for the minute change in θ by adjusting the slit width. There were also problems.

Therefore, conventionally, a technique has been proposed in which the slit width is adjusted by rotating the slit plate in conjunction with the θ rotation of the sample.

FIG. 2 shows a conventional X-ray diffraction apparatus using a technique of adjusting a slit width by rotating a slit plate. This X-ray diffractometer is disclosed in JP-A-58-18.
Reference numeral 1 in the figure denotes a line-focus type X-ray source, 2 denotes an incident X-ray, 3 denotes a sample, 4 denotes a diffracted X-ray, 5 denotes an X-ray counter, and 6 denotes a goniometer. And 7
Denotes a divergence slit, 8 denotes a stray radiation slit, and 9 denotes a light receiving slit.

In the apparatus shown in FIG. 2, the diverging slit 7 and the stray radiation slit 8 are rotated in conjunction with the θ rotation of the sample 3 to adjust the slit width. Arrows (a) and (b) in FIG.
Denotes a rotation direction of the slits 7 and 8, 10 and 11 denote a driving device that rotationally drives the slits 7 and 8, and 12 denotes a control processing device (computer). This control processor 12
Are connected to the respective slits 7, 8 via the driving devices 10, 11.
, The operation of the goniometer 6 is controlled, and the detection result of the X-ray counter 5 is processed.

[0010]

Incidentally, in the divergence slit 7 and the stray radiation slit 8 of the X-ray diffraction apparatus shown in FIG. 2, the projected area of the slit in the X-ray direction is controlled by controlling the rotation amount of the slit plate. The slit width can be adjusted in accordance with the θ rotation of the sample without changing the slit plate, and the slit width can be continuously adjusted even for minute changes in θ. The adjustment can measure the improvement of the measurement accuracy.

However, as shown in FIG.
When inclining with respect to the X-ray 16 passing through 5,
Due to the thickness T of the slit plate 15, the effective slit width d
Has a problem that it becomes narrower than the actual slit width D, and this tendency becomes larger as the rotation angle θ of the sample 3 becomes smaller. Also, the effective slit width d becomes eccentric with respect to the center of the actual slit width D. There is also the problem of doing.

[0012] Therefore, in the conventional measures of adjusting the effective slit width by the inclination of the slit plate, the range in which the slit width can be continuously adjusted in accordance with the θ rotation of the sample 3 with one slit plate is limited. After all, in order to cope with a wide range of change of θ, there is a problem that it is necessary to prepare several slit plates and replace them according to the range of θ. In addition, there is a problem that the movement control of the slit plate becomes complicated.

The present invention has been made in view of the above circumstances, and the adjustment of the slit width in conjunction with the θ rotation of the sample is continuously performed over the entire range of the θ rotation of the sample without the necessity of exchanging a slit plate or the like. X-ray diffraction that can be performed in a controlled manner and that the control process for adjusting the slit width is easy, and that the efficiency of the measurement operation and the measurement accuracy can be improved by automating the process of adjusting the slit width. It is intended to provide a device.

[0014]

An X-ray diffractometer according to claim 1 comprises an X-ray source, an X-ray detector for detecting diffracted X-rays from the sample, and the X-ray detector for the θ rotation of the sample. A goniometer for measuring the angle 2θ with respect to the θ rotation of the sample for 2θ scanning of the X-ray detector, a divergence slit arranged between the sample and the X-ray source for limiting the divergence angle of the incident X-ray, and a diffraction X A light receiving slit arranged at the focus position of the line and a scattering X
A scattering slit is provided between the X-ray detector and the sample to prevent rays from entering the X-ray detector.

The slit device used as the divergent slit is a guide member extending along the slit width direction, and a pair of X-ray shielding plates slidably supported by the guide member in the slit width direction. A feed screw member for moving the pair of X-ray shielding plates in a direction away from each other or in a direction approaching each other; a driving unit for rotationally driving the feed screw member; and the feed screw via the driving unit. A control processing device for controlling the rotation direction and the rotation amount of the member is provided.

Further, the pair of X-ray shielding plates are arranged on the same plane crossing the X-ray so that a distance between the mutually opposing ends becomes a slit width. And a left-hand threaded portion screwed to the other X-ray shielding plate is provided on the same axis.

When the slit width is changed, the control processing device firstly determines the amount of rotation of the feed screw member in the direction in which the X-ray shielding plates approach each other, by changing the distance between the X-ray shielding plates up to that time. The center of the slit width is set by instructing the end faces of the pair of X-ray shield plates to abut to each other, and then the feed screw member in the direction in which the X-ray shield plates are separated from each other. By accurately instructing the amount of rotation in accordance with the rotation angle θ of the sample, a slit width corresponding to the θ rotation of the sample is ensured.

An X-ray diffractometer according to a second aspect is an improved version of the X-ray diffractometer according to the first aspect, wherein the light receiving slit and the scattering slit use the same slit device as the divergent slit. I do.

[0019]

The X-ray diffractometer according to claim 1 uses a slit device for adjusting a slit width by sliding operation of a pair of X-ray shield plates as a divergence slit. Can be used without being inclined with respect to the X-ray optical path, so that there is no inconvenience in setting the slit width due to the influence of the thickness of the X-ray shielding plate, and when the slit width is changed. Is once X
Since the center of the slit width is set by abutting the end faces of the line shielding plates, the slit width can be accurately determined by relatively simple control without using a sensor or the like.

Therefore, the divergence angle of the incident X-ray can be controlled precisely and continuously over the entire range of the θ rotation of the sample without requiring replacement of the slit plate or the like.
The efficiency of the measurement operation is improved by automating the slit width adjustment processing for the lines, and the intensity of the diffracted X-rays is increased by optimizing the control of the divergence angle of the incident X-rays, thereby improving the measurement accuracy.

Further, the X-ray diffractometer according to claim 2 is
For the divergence slit, light receiving slit and scattering slit,
A slit device that adjusts the slit width by sliding a pair of X-ray shields. Thorough automation of slit width adjustment and precise slit width adjustment for both incident X-rays and diffracted X-rays. As a result, it is possible to maximize effects such as improvement of measurement work efficiency and improvement of measurement accuracy.

[0022]

1 and 4 show an embodiment of an X-ray diffraction apparatus according to the present invention. As shown in FIG. 4, the X-ray diffractometer according to this embodiment has an X-ray source 20.
And an X-ray detector 23 for detecting a diffracted X-ray 22 from the sample 21 and an angle 2θ of the sample 21 with respect to the θ rotation for the 2θ scanning of the X-ray detector 23 with respect to the θ rotation of the sample 21. A goniometer 24, a divergence slit 26 arranged between the sample 21 and the X-ray source 20 to limit the divergence angle of the incident X-ray 25, and a convergence position of the diffracted X-ray 22 (that is, on the focal circle) A light receiving slit 27 to be arranged;
A scattering slit 28 disposed between the X-ray detector 23 and the sample 21 to prevent the scattered X-rays from entering the X-ray detector 23;
, A solar slit 30 disposed between the light receiving slit 27 and the scattering slit 28, and the above-mentioned slits 26, 27, 28
Control unit 31 for controlling the operation of the goniometer 24 and processing the detection results of the X-ray detector 23, a display device 32 for displaying the processing results of the control processing unit 31, and a printer for hardcopying the measurement results 33 are provided.

The X-ray source 20 has a line focus which is long in the vertical direction (the direction perpendicular to the plane of FIG. 4), and the vertical divergence of the incident X-ray 25
The divergence angle in the horizontal plane (a plane parallel to the plane of the drawing) is further restricted by the divergence slit 26.

Reference numeral 24a in FIG. 2 denotes a rotation axis of the goniometer 24. The solar slit 30 on the light receiving side has a diffraction X
Suppress the vertical divergence of line 22 in the vertical direction. The solar slit 29 is fixed to a support frame common to the divergence slit 26, and the solar slit 30 is fixed to a support frame for 2θ scanning common to the light receiving slit 27 and the scattering slit 28.

The slit devices used for the slits 26, 27 and 28 have the same configuration. FIG. 1 is an enlarged view of a slit device S used for these slits 26, 27, 28.

The slit device S includes a guide member 40 extending along a slit width direction (that is, a direction crossing the X-ray flux 39 and a direction indicated by an arrow (a) in FIG. 1). A pair of X-ray shielding plates 41 and 42 slidably supported in the slit width direction, and each of the pair of X-ray shielding plates 41 and 42 is
A feed screw member 44 for moving the feed screw member 44 along with a driving means 45 for rotationally driving the feed screw member 44;
An interface is provided for connecting the driving means 45 to the control processing device 31 and notifying the driving means 45 of a control signal from the control processing device 31.

Here, the above-mentioned pair of X-ray shielding plates 41, 4
2 is supported movably in the slit width direction in the same plane crossing the X-ray by the blocks 41b and 42b fixed to the respective shield plate main bodies 41a and 42a being slidably fitted to the guide member 40. ing. And
The separation distance L between the mutually opposing ends of the respective shield plate bodies 41a and 42a is the slit width. Also,
The block 41b is fixedly provided with a female screw block 41c for a right-hand screw screwed with the feed screw member 44, and the block 42b is fixedly provided with a female screw block 42c for a left-hand screw screwed with the feed screw member 44. ing.

The feed screw member 44 includes a right-hand thread 44 a screwed to one X-ray shield plate 41 and the other X-ray shield plate 4.
2 is provided on the same axis with a left-hand threaded portion 44b screwed in the direction 2 so that the pair of X-ray shielding plates 41 and 42 are separated from each other by being rotationally driven by the driving means 45. Alternatively, they are moved in directions approaching each other.

In FIG. 1, reference numeral 50 denotes a support frame that rotatably supports the feed screw member 44 and also supports the guide member 40. The support frame 50 is provided with biasing means 51, 52 for pulling the X-ray shielding plates 41, 42 toward the support frame 50. These urging means 51 and 52 are controlled by the feed screw member
Eliminates backlash when moving the wire shielding plates 41 and 42,
Enables smooth and accurate feeding operation.

The driving means 45 uses a pulse motor capable of minutely rotating the feed screw member 44 in both positive and negative directions. The motor shaft of the pulse motor is connected to the feed screw via a shaft coupling C. It is connected to one end of the screw member 44.

The control processing device 31 is a computer, and controls the slit device S according to the rotation angle θ of the sample 21.
To control the movement of each of the X-ray shielding plates 41 and 42, or the operation of the goniometer 24,
The detection result of the line detector 23 is processed.

When changing the slit width, the control processor 31 first moves the X-ray shielding plates 41 and 42 in a direction in which they approach each other. At this time, the rotation amount of the feed screw member 44 instructed by the control processing device 31 to the drive means 45 is set to be larger than the distance between the X-ray shielding plates 41 and 42 up to that time.

For example, if a 90-pulse rotation instruction is given to the driving means 45, a rotation instruction for 100 pulses is issued in the case of the separation distance L at which the ends of the X-ray shielding plates 41 and 42 are in close contact with each other. Thereby, the end faces of the pair of X-ray shielding plates 41 and 42 collide with each other, and the position where the end faces contact each other is set as the center of the slit width, so that the center can be easily centered without using a position detection sensor or the like. Can be.

When the centering by hitting the X-ray shielding plates 41 and 42 is completed, a predetermined slit width is obtained using the position where the two X-ray shielding plates 41 and 42 meet as a reference position. The X-ray shielding plates 41 and 42 are moved in a direction in which they are separated from each other. At this time, the rotation amount of the feed screw member 44 instructed by the control processing device 31 to the driving means 45 is accurately instructed according to the rotation angle θ of the sample 21. Thereby, each slit device S can ensure a slit width corresponding to the θ rotation of the sample 21 accurately.

The data instructed when the X-ray shielding plates 41 and 42 are separated from each other is stored in a memory inside the control processing unit 31, and then, the end faces of the X-ray shielding plates 41 and 42 are bumped against each other and then again. Use as reference data for centering.

As described above, in one embodiment, the slit device S employed for each of the slits 26, 27, 28 adjusts the slit width by sliding the pair of X-ray shielding plates 41, 42. Each of the X-ray shielding plates 41 and 42 can be used in a state where it is always perpendicular to the X-ray optical path without being inclined. Therefore, the X-ray shielding plates 41, 4
There is no inconvenience in setting the slit width such that the effective slit width is eccentric from the actual slit width or the adjustment range of the slit width is limited due to the influence of the plate thickness of 2.

When the slit width is to be changed, the slit device S is used to center the slit width by bringing the end faces of the X-ray shielding plates 41 and 42 into contact with each other. Even without this, the slit width can be accurately determined by relatively simple control.

Therefore, each of the slits 26, 27, 28
In the above, the slit width adjustment linked to the θ rotation of the sample 21 can be continuously performed over the entire range of the θ rotation of the sample without the necessity of exchanging the slit plate or the like, and the slit width is adjusted. Control process is easy,
It is possible to improve the efficiency of measurement work and the accuracy of measurement by automating the process of adjusting the slit width.

The use of the slit device S for the divergence slit 26 means that the divergence angle of the incident X-ray 25 is precisely controlled, and the X-ray irradiation area on the sample 21 is expanded more than necessary. This is important in preventing the shortage and improving the intensity of the diffracted X-ray by optimizing the divergence angle control of the incident X-ray. The fact that the slit device S is used for the light receiving slit 27 and the scattering slit 28 is as follows.
The divergence slit 26 has an important meaning in preventing the intensity of the diffracted X-rays improved by the divergence slit 26 and preventing the SN ratio from lowering.

Therefore, in one embodiment, the divergent slit 2
6. The slit device S for automatically adjusting the slit width is used for all of the light receiving slit 27 and the scattering slit 28, so that the effect of the automatic slit width adjustment is maximized. However, if the slit device S is used for at least the diverging slit 26, even if a known slit width adjusting technique is used for some of the other slits, the measurement work efficiency is not sufficient as in the embodiment. And the effect of improving measurement accuracy can be obtained.

[0041]

The X-ray diffractometer according to the first aspect uses a slit device for adjusting the slit width by sliding operation of a pair of X-ray shielding plates as a divergent slit. X of each shielding plate
Since it can be used without being inclined with respect to the X-ray optical path, there is no inconvenience in setting the slit width due to the influence of the thickness of the X-ray shielding plate. Since the center of the slit width is set by abutting the end faces of the line shielding plates, the slit width can be accurately determined by relatively simple control without using a sensor or the like.

Therefore, the divergence angle of the incident X-ray can be controlled precisely and continuously over the entire range of the θ rotation of the sample without the necessity of replacing the slit plate or the like.
The efficiency of the measurement operation is improved by automating the slit width adjustment processing for the lines, and the intensity of the diffracted X-rays is increased by optimizing the control of the divergence angle of the incident X-rays, thereby improving the measurement accuracy.

The X-ray diffractometer according to claim 2 is
For the divergence slit, light receiving slit and scattering slit,
A slit device that adjusts the slit width by sliding a pair of X-ray shields. Thorough automation of slit width adjustment and precise slit width adjustment for both incident X-rays and diffracted X-rays. As a result, it is possible to maximize effects such as improvement of measurement work efficiency and improvement of measurement accuracy.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a main part of an embodiment of the present invention.

FIG. 2 is an explanatory diagram of a conventional X-ray diffraction apparatus that automatically adjusts a slit width.

FIG. 3 is an explanatory view of a problem of a conventional slit device.

FIG. 4 is an overall configuration diagram of an embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 20 X-ray source 21 Sample 22 Diffracted X-ray 23 X-ray detector 24 Goniometer 25 Incident X-ray 26 Diverging slit 27 Receiving slit 28 Scattering slit 31 Control processing device S Slit device 40 Guide member 41, 42 X-ray shielding plate 44 Feed screw Member 45 Driving means 50 Support frame 51, 52 Urging means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-58-182543 (JP, A) JP-A-54-84794 (JP, A) JP-A-3-251799 (JP, A) JP-A-3- 2698 (JP, A) JP-A-4-324348 (JP, A) JP-A-4-63056 (JP, U) JP-A-3-110359 (JP, U) (58) Fields investigated (Int. ⁷ , DB name) G21K 1/06 G01N 23/20

Claims (2)

(57) [Claims] 1. An X-ray source, an X-ray detector for detecting diffracted X-rays from a sample, and an angle 2 with respect to the θ rotation of the sample for 2θ scanning of the X-ray detector with respect to the θ rotation of the sample.
a goniometer for measuring θ, a divergence slit arranged between the sample and the X-ray source to limit the divergence angle of the incident X-ray, and a light receiving slit arranged at a focus position of the diffracted X-ray,
An X-ray diffractometer having a scattering slit disposed between the X-ray detector and a sample for preventing scattered X-rays from entering the X-ray detector, wherein the X-ray diffraction device is used as the diverging slit. The slit device includes a guide member extending along the slit width direction, and mutual ends slidably supported by the guide member in the slit width direction and facing each other on the same plane crossing the X-ray. A pair of Xs whose separation distance between the parts is the slit width
A line shield plate, and a right-hand threaded portion screwed to one of the pair of X-ray shield plates and a left-handed threaded portion screwed to the other are mounted on the same axis and driven to rotate, thereby forming the pair of X-ray shield plates. A feed screw member for moving each of the X-ray shielding plates in a direction away from each other or in a direction approaching each other; a driving unit for rotationally driving the feed screw member; a rotation direction of the feed screw member by the driving unit; A control processing device that controls the amount of rotation, and when changing the slit width, the control processing device firstly adjusts the amount of rotation of the feed screw member in the direction in which the X-ray shielding plates approach each other. The center of the slit width is performed by instructing the end faces of the pair of X-ray shielding plates to be larger than the separation distance between the X-ray shielding plates up to and then contacting the X-ray shielding plates. Mutually separated An X-ray diffraction apparatus characterized in that a slit width according to the rotation of the sample is secured by accurately indicating the amount of rotation of the feed screw member in the interposed direction according to the rotation angle θ of the sample. 2. The X-ray diffraction apparatus according to claim 1, wherein a slit device having the same configuration as a divergence slit is used for the light receiving slit and the scattering slit.