JPH01265146A - X-ray diffraction device - Google Patents

Abstract

PURPOSE:To eliminate the need for a filter and crystal for single coloration by attenuating the intensity of the incident X-ray on a semiconductor X-ray detector having energy resolving power when the intensity of the incident X-ray on said detector attains a specified value or above. CONSTITUTION:The surface of a sample 24 is irradiated by the characteristic X-ray P emitted from an X-ray source 1. A sample turn table 22 and an angle measuring table 23 are rotated in this state at theta and 2theta angular speeds respectively. The X-ray (q) coming from the direction of the sample 24 is thereby projected to the semiconductor X-ray detector 3. The total number of the pulses transmitted from the semiconductor X-ray detector 3 is counted by a scaler 51. The pulses are resolved by energy and the counting by each of energy is executed by a multichannel analyzer 52. The count value of the scaler 51 and the prescribed count value are compared and an attenuation plate 41 is controlled according to the results of the comparison in an arithmetic control means 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an X-ray diffraction apparatus, and in particular, an X-ray detector for measuring the diffraction angle of diffracted X-rays diffracted from a sample. This invention relates to a semiconductor X-ray detector constructed with a high resolution semiconductor X-ray detector.

[Prior Art] An X-ray diffraction apparatus measures the diffraction angle of diffracted X-rays diffracted from a crystalline sample when monochromatic X-rays are irradiated on the sample. is rotated at a rotational speed of θ, and on the other hand, an X-ray detector for detecting diffracted X-rays diffracted from the sample is rotated at a rotational speed of 2θ around the rotation center of the sample in synchronization with the rotation of the sample. A so-called goniometer is used.

In this case, a Geiger counter, a proportional counter, a scintillation counter, or the like is used as the X-ray detector mounted on the goniometer. That is, in principle, the conventional Xi diffraction apparatus described above
The X-ray is a monochromatic X-ray, and the X-ray detector measures the intensity of the diffracted X-ray that is diffracted in a specific direction by satisfying Bragg's diffraction conditions within the sample. Therefore, the X-ray detector used in a conventional X-ray diffraction device only needs to be able to accurately determine the intensity of this monochromatic X-ray, and the energy resolution is determined by the pulse height analyzer etc. connected to this detector. It was believed that it was sufficient to remove a certain level of noise components.

[Problems to be Solved by the Invention] Incidentally, in the conventional X-ray diffraction apparatus, when the monochromaticity of the X-rays irradiated to the sample is poor, the detected value measured by the X-ray detector is not necessarily This cannot be said to accurately represent the crystal information of the sample.

Therefore, in order to improve the measurement accuracy of the conventional X-ray diffraction apparatus, it is necessary to improve the monochromaticity of the X-rays irradiated onto the sample.

In order to perform this monochromatic treatment, for example, it was necessary to irradiate the sample with the irradiated X-rays through a monochromatic filter or through a monochromatic crystal.

However, due to the monochromatic operation using such filters or crystals, the intensity of the X-rays is significantly attenuated, and therefore, from the viewpoint of the S/N ratio, there is a certain limit to the improvement of measurement accuracy by this method. The only effective way to further improve accuracy is to make the X-ray generator extremely large, but even this has its limits.

SUMMARY OF THE INVENTION An object of the present invention is to provide an X-ray diffraction apparatus that eliminates the above-mentioned drawbacks and makes it possible to achieve measurement accuracy that was not possible with conventional X-ray diffraction apparatuses.

[Means for Solving the Problems] The present invention uses a semiconductor X-ray detector having energy resolution as an X-ray detector for detecting diffracted X-rays, and also reduces the intensity of X-rays incident on the semiconductor X-ray detector. This device is equipped with an attenuation means that attenuates the intensity of the X-rays incident on the detector when the only the diffracted X-rays from the sample can be detected,
This makes it possible to secure a high S/N ratio that could not be obtained conventionally, and has the following configuration.

The crystalline sample is rotated to change the incident angle of the X-rays irradiated onto the sample, and an X-ray detector for detecting the diffracted X-rays diffracted from the sample is rotated around the rotation center of the sample. In an X-ray diffraction apparatus that measures the diffraction angle of diffracted X-rays from the sample by rotating it at a speed that has a constant relationship with the rotation speed of the sample, the X-ray detector is made of a semiconductor having energy resolution. X
ray detector, and is provided with an X-ray attenuation means that attenuates the intensity of the X-rays incident on the semiconductor X-ray detector when the intensity of the X-rays incident on the semiconductor X-ray detector exceeds a certain value. An X-ray diffraction device characterized by:

[Operation] According to the above configuration, among the X-rays that reach the X-ray detector at the specific angle, there is a certain amount of X-rays that have been diffracted by the specific crystal lattice of the sample while satisfying the Bragg diffraction condition. It includes X-rays with a specific wavelength and X-rays with other wavelength components, but each of these X-rays has a
It is decomposed and detected with extremely high resolution. Moreover, when the detected X-ray intensity exceeds a certain value, the X-ray attenuating means attenuates the intensity of the X-rays incident on the X-ray detector. There is also no fear that the energy resolution of the X-ray detector will be degraded by the input.

Therefore, by measuring the intensity of only the wavelength component of the diffracted X-ray that satisfies the Bragg diffraction condition among the X-rays decomposed into each wavelength component (each energy), it is possible to
It can perform measurements similar to a line diffraction device.

In this case, since the semiconductor detector has much better energy resolution than the X-ray detector used in conventional X-ray diffraction devices, Make the lines monochrome in advance, or
Even without performing any processing such as making the diffracted X-rays diffracted from the sample monochromatic before entering the detector, Bragg's diffraction conditions are satisfied and only the incident X-rays of a specific wavelength are separated from other X-rays. It is possible to clearly distinguish and measure with high sensitivity and accuracy.

Therefore, it enables measurements with a significantly higher S/N ratio than when using conventional monochromatic filters or monochrome crystals.

[Example] FIG. 1 is a diagram showing the configuration of an X-ray diffraction apparatus according to an example of the present invention.

In the figure, code 1 is an X-ray source, code 2 is a goniometer,
3 is a semiconductor X-ray detector, 4 is an X-ray attenuation means, 5 is an X-ray counting means, 6 is an arithmetic control means, and 7 is a recording means.

The X-ray source 1 is constituted by an X-ray tube whose target is Cu, Mo, CO, or the like, and is capable of emitting characteristic X-rays corresponding to the target.

The goniometer 2 also includes a goniometer main body 21, a sample rotary table 22 rotatably provided on the goniometer main body 21, and a Jll angle rotatably provided around a rotation center O of the sample rotary table 22. It consists of a stand 23, an X-ray detector 3 placed 11 on the angle measuring stand 23, and an X-ray attenuation means 4 capable of attenuating the X-rays incident on the X-ray detector 3. .

The goniometer main body 21 has a built-in drive mechanism that rotates the sample rotating table 22 at an angular velocity of θ and simultaneously rotates the angle measuring table 23 at an angular velocity of 2θ.

Further, the semiconductor X-ray detector 3 uses a semiconductor such as Sl or Ge as a detection element. This semiconductor X-ray detector 3 has a wave height proportional to the energy (wavelength) of the X-rays incident on the X-ray detector 3, and sends out a number of pulse signals proportional to the intensity of the incident X-rays. , the energy resolution is significantly higher than that of proportional counters, scintillation counters, etc. In other words, for example, when the energy of the X-ray to be detected is around 5.9 KeV, the energy resolution = ΔE/E < 0.03. be.

Further, the X-ray attenuation means 4 includes an attenuation plate 5 having a constant transmittance for characteristic X-rays emitted from the X-ray source 1.
1, and a drive device 42 that drives the attenuation plate 41 to insert and remove the attenuation plate 41 into and out of the X-ray optical path incident on the X-ray detector 3.

Further, the counting means 5 includes an anti-Kohler 51 that counts the total number of pulses sent out from the semiconductor XL detector 3;
It is comprised of a multi-channel analyzer 52 that separates and counts the pulse signals sent from the semiconductor X-ray detector 3 into energy units.

Further, the arithmetic control means 6 inputs the count value for each energy sent out from the multi-channel analyzer 52, stores it one after another in correspondence with the input time, and also stores the counted value for each energy sent out from the scaler 51 one after another in correspondence with the input time. Input the count value and perform the following calculation control according to the count value.

That is, first, the count value of the scaler 51 is compared with a predetermined constant count value. If the result of this comparison is that the count value of the scaler is larger, the X-ray attenuation is The driving device 42 of the means 4 is driven to insert the X-ray attenuation plate 41 into the X-ray optical path incident on the X-ray detector 3.

At the same time, the count value of X-rays of each energy sent out from the multi-channel analyzer 52 after the insertion of the X-ray attenuation plate 41 is calculated by the amount reduced by the insertion of the attenuation plate 41. A count value corresponding to a numerical value is added and stored.

On the other hand, when the count value of the scaler 51 is smaller, the X-ray attenuation plate 41 is removed from the X-ray optical path, contrary to the above. In this case, the above addition! Of course, the L operation can be canceled. The count values stored in this way can be sent to the outside as necessary.

The recording means 7 records and displays the count values of X-rays of specific energy sent out from the arithmetic and control means 6 one after another.

In the above-described configuration, the following procedure is used to perform measurement using the X-ray diffraction method.

First, a crystalline sample 24 to be measured is placed on the sample rotating table 22 of the goniometer 2. Then, the surface of the sample 24 is irradiated with characteristic Xap emitted from the X-ray source 1. In this state, the sample rotating table 22 and the angle measuring table 23
and are rotated at angular velocities of θ and 2θ, respectively. As a result, Xlq coming from the direction of the sample 24 is incident on the semiconductor X-ray detector 3. In this incident X-ray q,
In addition to the diffracted X-rays in which the characteristic X-rays (X-rays having a specific single wavelength) emitted from the X-ray source 1 are diffracted by satisfying Bragg's diffraction conditions on a specific crystal plane of the sample 24, contains noise components with various energies (wavelengths).

The incident X-rays are converted by the semiconductor X-ray detector 3 into electrical pulses having a wave height proportional to their respective energies, the number of which is proportional to their intensity, and sent to the counting means 5.

In this counting means 5, the total number of pulses (regardless of energy) sent out from the semiconductor X-ray detector 3 is counted by the scaler 51. Further, in parallel with this, the multi-channel analyzer 52 decomposes the energy into each energy and counts each energy.

Then, each count value is sent to the arithmetic control means 6.

As described above, in this arithmetic control means 6, the processing processes of comparing the count value of the scaler 51 with a predetermined count value, controlling the damping plate 41 based on the comparison result, and storing are performed.

In this case, the predetermined constant count value is selected to be smaller than the maximum count value that the semiconductor X-ray detector 3 can count without reducing energy resolution. As a result, even if the X-rays coming from the sample 24 are strong enough to exceed the maximum count value, the intensity of the X-rays can be maintained without reducing the resolution of the semiconductor X-ray detector 3. can be detected accurately.

The characteristic X emitted from the X-ray source 1 is then
By selecting the count value of diffracted X-rays (X-rays having a specific single wavelength) that satisfy the Pla-Lag diffraction conditions on a specific crystal plane of the sample 24, X-ray diffraction data similar to that obtained by the X-ray diffraction apparatus can be obtained.

In this case, in this embodiment, the count value of the diffracted X-rays is almost entirely based on only the diffraction lines from specific crystal planes. This means that noise components other than the diffraction lines (fluorescent X-rays from the sample, different wavelength components included in the characteristic X-rays emitted from the X-ray source 1, and other noise components) are
This is because it is almost completely removed by the line detector 3 and multichannel analyzer 52. Moreover, in this case, there is no need to use a monochromator or the like to remove noise components as in the past, so there is no need to use a powerful X-ray generator as an X@ source, and the S/N ratio can be improved. Extremely high measurements can be made.

[Effects of the Invention] As detailed above, the present invention provides an X-ray system for detecting diffracted X-rays.
A semiconductor X-ray detector having energy resolution is used as a ray detector, and the intensity of the X-rays incident on the semiconductor X-ray detector is determined when the intensity of the X-rays incident on the semiconductor X-ray detector exceeds a certain value. This system is equipped with an attenuating means for attenuating the X-rays, and this makes it possible to detect only the diffracted X-rays from the sample without using a filter or crystal for monochromating as in the conventional example. This makes it possible to perform measurements with a high S/N ratio, which was previously impossible.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an X+41 diffraction apparatus according to an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... X-ray source, 2... Goniometer, 22... Sample rotating table, 23... Angle measuring table, 24... Sample, 3... Semiconductor X-ray detector, 4... xis weak pitcher 5... Counting means, 6... Arithmetic control means, 7... Recording means. Applicant Mac Science Co., Ltd.

Claims (1)

[Claims] A crystalline sample is rotated to change the incident angle of X-rays irradiated to the sample, and an X-ray detector for detecting diffracted X-rays diffracted from the sample is set at the center of rotation of the sample. An X-ray diffraction apparatus configured to measure the diffraction angle of diffracted X-rays from the sample by rotating the sample at a speed having a constant relationship with the rotation speed of the sample, the X-ray detector comprising: , a semiconductor X with energy resolution
ray detector, and is provided with an X-ray attenuation means that attenuates the intensity of the X-rays incident on the semiconductor X-ray detector when the intensity of the X-rays incident on the semiconductor X-ray detector exceeds a certain value. An X-ray diffraction device characterized by: