JP2000292375A - X-ray diffraction device and measuring method of sample using this device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously measure the reaction quantity of a sample with a gas and the diffraction result such as crystal structure of the sample by connecting an evacuating means, a gas introducing means, and a gas quantity measuring means to a chamber part. SOLUTION: This device comprises a diffusion pump 5, a rotary pump 6 and the like as evacuating means, a gas cylinder 7 or the like filled with an inert gas as gas introducing means, and a pressure gauge 8, a precise pressure gauge 9, a high vacuum gauge 10 and the like as gas quantity measuring means. A heater consists of a Ta thin film heater, and it is provided on the X-ray emitting-side back surface of a sample. The pressure within a chamber 2 and the temperature are set to about 0-10 atm. and about 20-500 deg.C by these means, and the gas quantity according to the pressure within the chamber 2 is measured. In the case of a hydrogen storage alloy sample, for example, the hydrogen gas quantity or hydrogen storage quantity is measured from the equilibrated hydrogen pressure, and the lattice constant and crystal structure of the hydrogen storage alloy are measured by X-ray diffraction. This is intermittently performed with the lapse of time, whereby the hydrogen storage quantity, the lattice constant change, and the form change of crystal can be simultaneously measured.

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 a method for measuring a sample using the apparatus. More specifically, the present invention can simultaneously measure a reaction amount of a sample with a gas and a diffraction result such as a crystal structure of the sample. The present invention relates to an X-ray diffraction apparatus and a method for measuring a sample using the apparatus.

[0002]

2. Description of the Related Art In order to analyze the crystal structure of a sample using radiation, in particular, X-rays, an X-ray camera that captures diffraction lines on a film or directly counts diffraction lines. A four-axis automatic diffractometer that measures in a tube is used. In general, a sample irradiated with X-rays and diffracted has a size such that the maximum length does not exceed 1 mm.
This sample is attached to the tip of a sample plate made of a substance that is less affected by X-ray diffraction. Then, the sample plate is mounted on a goniometer head, and the goniometer head is fixed to a diffractometer. A method of irradiating a sample with X-rays emitted from an X-ray source and rotating the crystal in order to efficiently collect, for example, diffraction lines distributed in a three-dimensional space in the case of a crystal has been adopted.

In such a method of measuring a sample using an X-ray diffractometer, an X-ray diffractometer capable of measuring under vacuum or gas pressure or at a high temperature has been reported (for example, Japanese Patent Application Laid-Open No. 58-147634). Gazette), an X-ray diffractometer capable of directly measuring a reaction amount of a sample with a gas such as hydrogen gas and a diffraction result has not yet been reported.

For example, when an X-ray diffractometer is used to measure a change in the lattice constant of the hydrogen storage alloy with respect to the hydrogen storage amount or a change in the form of the alloy due to phase transformation, the relationship between the hydrogen storage amount and the equilibrium hydrogen pressure is measured in advance under the same conditions. Incidentally, in an actual X-ray diffractometer, it is necessary to estimate the hydrogen storage amount from the hydrogen pressure based on the result. For this reason, there is a problem that the measuring method becomes complicated.

A heater for heating a sample fixed in a chamber portion of an X-ray diffraction apparatus has a resistor made of a tungsten wire or the like wound on the outer periphery of the sample. May inhibit. Actually, the resistor on the back side of the sample is at a distance close to the sample, but the thin-line resistor is arranged on the front side of the sample at a distance so as not to affect the diffraction phenomenon.
For this reason, thermal efficiency is poor and it is difficult to obtain a uniform temperature range. In addition, since the uniform tropical zone cannot be taken widely, the X-ray irradiation area of the measurement sample is small, so that the obtained diffraction line is also limited.

When a resistor is used as the heater, the heating must be performed while gradually releasing impurities contained in the resistor when the temperature is raised. If the temperature is not raised and lowered gradually, the life of the resistor will be shortened. Also, if impurities released from the resistor are not removed,
The sample may be poisoned by oxidation or the like by impurities.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an X-ray diffractometer capable of simultaneously measuring a diffraction result such as a crystal structure of a sample with respect to a reaction amount of the sample with a gas and a method of measuring a sample using the device. It is in.

[0008]

As a result of the study, the present inventors have found that the above-mentioned object can be achieved by connecting the vacuum exhaust means, the gas introducing means, and the gas amount measuring means to the chamber. I learned.

The present invention has been made on the basis of the above findings, and has an X-ray generating means, a chamber, a goniometer and an X-ray generator.
An X-ray diffractometer, comprising: a X-ray detector for irradiating a sample fixed in the chamber with X-rays and measuring a diffraction line from the sample. It is an object of the present invention to provide an X-ray diffraction apparatus characterized by connecting an exhaust means, a gas introducing means for introducing various gases into the chamber, and a gas amount measuring means for measuring a gas change amount in the chamber.

The present invention also relates to a method for irradiating a sample fixed in the chamber portion with X-rays by using the X-ray diffractometer and measuring the diffraction line of the sample. It is an object of the present invention to provide a method for measuring a sample, wherein the amount is measured from the pressure, and simultaneously the diffraction line from the sample is measured.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below. FIG. 1 shows an embodiment of the present invention, X
FIG. 2 is an overall image diagram of the line diffraction apparatus. In FIG. 1, X
The main part of the X-ray diffraction apparatus is composed of the X-ray generation means 1, the chamber 2, the goniometer 3, and the X-ray detector 4. Using such an X-ray diffraction apparatus main body, the sample fixed in the chamber section 2 is irradiated with X-rays from the X-ray generation means 1, and the X-ray detector 4 measures diffraction rays. Here, the goniometer 3 measures an X-ray diffraction angle. Such an X-ray diffractometer is a commonly used device.

The X-ray diffractometer of the present invention comprises a vacuum exhaust means for evacuating the chamber to the chamber 2, a gas introducing means for introducing various gases into the chamber, and a gas for measuring the gas amount in the chamber. Connect the quantity measuring means.

The evacuation means includes a diffusion pump 5 and a rotary pump 6, and evacuates the chamber 2. The gas introducing means includes a gas cylinder 7 filled with an inert gas such as a hydrogen gas, a helium gas, and a nitrogen gas.
The gas amount measuring means includes a pressure gauge 8, a precision pressure gauge 9, a high vacuum gauge 10, and the like. The evacuation means and the gas introduction means are crossed by the gas amount measuring means, and are finally connected to the chamber 2.

In the X-ray diffractometer of the present invention, the heater for heating the sample fixed in the chamber section 2 is a Ta-based thin film heater, and the X-ray diffraction of the sample is
It is desirable to be provided on the back side on the radiation side. This Ta-based thin film heater can be obtained by a sputtering method or a vapor deposition method, and preferably obtained by a sputtering method.

FIG. 2 is a schematic sectional view showing an example of the chamber section 2 using such a heater. FIG. 3 shows a partial exploded view of the chamber section 2. 2 to 3, 11 is an X-ray window, 12 is a sample, 13 is a sample plate, 14
Is a sample holder, 15 is a heater, 16 is a sample side fixture, 17 is a sample front fixture, 18 is a sample front fixture holding member, 19 is a goniometer stage, and 20 is a vacuum /
Each shows a gas inlet.

Sample 1 having a maximum of 30 × 20 mm and a thickness of 2 mm
2 is removably fixed to the sample holder 13 on the sample plate 13 packed therein, and is held in a vertical manner. The sample holder 13 is detachably fixed to the sample holder 14. The sample 12 is fixed by a sample side fixture 16 and a sample front fixture 17, and the sample front fixture 17 is fixed by a sample front fixture holding member 18. Further, since both the X-ray window 11 and the sample front fixture 17 are made of metal beryllium, even if X-rays pass through the X-ray window 11 and the like, they do not hinder radiation and diffraction.

The heater 15 is provided on the back surface of the sample 12, that is, on the back surface on the X-ray irradiation side.
The heater 15 is a Ta-based thin film heater having a face plate shape. The use of such a heater makes it possible to reduce the temperature gradient in the sample plane. Further, since the heater is a Ta-based thin film heater, the temperature can be raised and lowered rapidly, the amount of release of impurity gas is extremely small, and the handling becomes very easy.

Next, the method for measuring a sample according to the present invention will be described. In the present invention, the amount of gas change in the chamber is measured from the pressure, and at the same time, the diffraction line from the sample is measured.

That is, the pressure in the chamber is reduced from vacuum to 10 atm by a vacuum exhaust system and a gas introduction system.
Further, the temperature is set to a room temperature (20 ° C.) to 50 by a heater.
0 ° C. For example, at 200 ° C. and 5 atm. Then, the amount of gas accompanying the pressure in the chamber is measured.
For example, when a hydrogen storage alloy is used as a sample, the amount of hydrogen gas and thus the amount of hydrogen storage are measured from the equilibrium hydrogen pressure, and the lattice constant and crystal structure of the hydrogen storage alloy at this time are measured by X-ray diffraction. Therefore, by performing such a measurement over time or intermittently, it becomes possible to simultaneously measure the change in lattice constant with respect to the change in the hydrogen storage amount, temperature, and pressure, and the morphological change of the crystal accompanying the phase transition. .

When the hydrogen storage amount is measured at a certain temperature, during the phase transformation, the equilibrium hydrogen pressure is constant without depending on the hydrogen storage amount. Therefore, it is difficult to estimate the hydrogen storage amount from the hydrogen pressure. On the other hand, in the present invention, the hydrogen storage amount can always be determined even when the equilibrium pressure is constant.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on embodiments.

Example 1 The temperature dependence of nickel powder was evaluated using the X-ray diffraction apparatus shown in FIGS. The results are shown in FIG.

Example 2 X-ray diffraction of a LaNi ₅ alloy was performed using the X-ray diffraction apparatus shown in FIGS. The results are shown in FIG.

Example 3 Using the X-ray diffractometer shown in FIGS. 1 to 3, the effect of the amount of hydrogen occlusion on the amount of phase transformation of the LaNi ₅ alloy was evaluated. The results are shown in FIG.

Example 4 Using the X-ray diffractometer shown in FIGS. 1 to 3, the influence of the hydrogen storage amount on the lattice constant of the LaNi ₅ alloy was evaluated. The results are shown in FIG.

[0026]

As described above, according to the sample measuring method using the X-ray diffractometer of the present invention, it is possible to simultaneously measure the diffraction result such as the structure of the sample with respect to the reaction amount of the sample with the gas.

[Brief description of the drawings]

FIG. 1 is an overall image diagram of an X-ray diffraction apparatus showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view showing an example of a chamber section used in the present invention.

FIG. 3 is a partially exploded view of a chamber portion used in the present invention.

FIG. 4 is a graph showing the temperature dependence of nickel powder.

FIG. 5 is an X-ray diffraction diagram of a LaNi ₅ alloy.

FIG. 6 is a graph showing the relationship between the amount of phase transformation and the amount of hydrogen occlusion of a LaNi ₅ alloy.

FIG. 7 is a graph showing the relationship between the lattice constant of LaNi ₅ alloy and the amount of hydrogen occlusion.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 X-ray generation means 2 Chamber part 3 Goniometer 4 X-ray detector 5 Diffusion pump 6 Rotary pump 7 Gas cylinder 8 Pressure gauge 9 Precision pressure gauge 10 High vacuum gauge 11 X-ray window 12 Sample 13 Sample plate 14 Sample holder 15 Heater 16 Sample side fixture 17 Sample front fixture 18 Sample front fixture holder 19 Goniometer stage 20 Vacuum / gas inlet

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinichi Inoue 1333-2, Hara-shi, Ageo-shi, Saitama Mitsui Mining & Smelting Co., Ltd. (72) Inventor Kenji Tomonari 1333-2, Hara-shi, Ageo-shi, Saitama Mitsui Kinzoku Mining F-term in company research institute (reference) 2G001 AA01 BA18 CA01 GA16 GA17 JA14 KA08 KA20 LA02 MA04 MA05 NA11 NA17 PA07 QA01 QA10

Claims (3)

[Claims] An X-ray which includes an X-ray generating means, a chamber, a goniometer, and an X-ray detector, irradiates a sample fixed in the chamber with X-rays, and measures diffraction rays from the sample. In the diffraction apparatus, a vacuum evacuation unit for evacuating the chamber unit, a gas introduction unit for introducing various gases into the chamber unit, and a gas amount measurement unit for measuring a gas change amount of the chamber are connected to the chamber unit. An X-ray diffraction apparatus, comprising: 2. The heater according to claim 1, wherein the heater for heating the sample fixed in the chamber is a Ta-based thin film heater, and is provided on the back surface of the sample on the X-ray irradiation side. X-ray diffractometer. 3. A method for irradiating a sample fixed in the chamber portion with X-rays using the X-ray diffraction device according to claim 1 and measuring a diffraction line of the sample, wherein the gas in the chamber portion is measured. A method for measuring a sample, comprising measuring a change amount from a pressure and simultaneously measuring a diffraction line from the sample. A method for measuring a sample, comprising: measuring a gas change amount in the chamber from a pressure and simultaneously measuring a diffraction line from the sample.