JPH1038772A - Measuring method for liquid sample, sample holder and x-ray diffractometer therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure a liquid sample containing a substance of different specific gravity accurately and quickly while enhancing the accuracy. SOLUTION: When analysis of a substance is performed through X-ray diffraction by irradiating a specified sample with X-rays and measuring the intensity of X-rays diffracted by the sample, a sample holder 1 is filled with a liquid sample containing a substance of different specific gravity and enclosed and then the sample holder 1 is rotated at a rotational speed of about 3 revolutions/ sec or lower (except 0 revolutions/sec) using a powder X-ray diffractometer having a sample measuring plane extending in parallel with the gravitational direction. Consequently, the liquid sample in the sample holder 1 is stirred forcibly and homogenized before being measured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for measuring a liquid sample, a sample holder used for the method, and an X-ray diffractometer.

[0002]

2. Description of the Related Art There is a powder X-ray diffraction method for analyzing a solid sample by X-ray diffraction, and a sample holder as shown in FIG. 6 is used. FIG. 6 is a perspective view of a conventional sample holder. The sample holder 31 has a concave portion 31a on the measurement surface to be irradiated with X-rays, and the concave portion 31a is filled with a powder sample and formed into a thin plate shape. And measure. The sample holder 31 is made of aluminum and is used in an upright state as shown in FIG. 6 during measurement.

[0003] In the sample holder, a liquid sample cannot be measured, but the liquid is powdered by drying or the like for measurement. For example, in a method for producing ceramics, there is a wet mixing method in which a solvent and a binder are mixed during mixing and pulverization of raw materials and after mixing and pulverization after calcination, and a crystal of ceramic powder in a ceramic slurry in which a solvent and a binder are mixed is used. The mixing / crushing time is determined from the state. Since the sample holder 31 shown in FIG. 6 can measure only a powder state, the solvent and binder were removed from the ceramic slurry by dry evaporation or the like, and the measurement was performed in a powder state.

[0004]

However, it takes a long time to remove the solvent and the binder from the ceramic slurry, and there is a problem that the measurement time of one sample becomes long.
In addition, there is a problem that the crystal structure of the ceramic powder changes between the slurry state and the powder state, and that the reaction is accelerated during drying and evaporation, so that the crystal structure of the ceramic powder in the slurry state cannot be measured accurately. . In addition, when evaluating the distortion of the crystal during grinding to determine the grinding time,
It took several hours to remove the solvent and the binder, and it took a long time to determine the pulverization time, which was a factor of lengthening the analysis period.

There are sample holders and X-ray diffractometers that can measure liquid samples. However, if substances having different specific gravities are contained, the component distribution in the upper and lower phases of the liquid changes with time due to the difference in specific gravity. It had the disadvantage of inaccurate results. For example, in the case of ceramic slurry, as the measurement time becomes longer, the ceramic raw material powder and ceramic calcined powder in the ceramic slurry settle, and the phase containing a large amount of solvent and binder and the ceramic raw material powder and ceramic calcined powder Was separated into phases containing a large amount of, and the measurement results varied.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and a method for measuring a liquid sample which realizes accurate measurement of a liquid sample containing substances having different specific gravities and which is quick and has improved accuracy of measured values. An object of the present invention is to provide a sample holder and an X-ray diffractometer for use therein.

[0007]

That is, a first aspect of the present invention relates to X-ray diffraction in which a predetermined sample is irradiated with X-rays, the intensity of the X-ray diffracted by the sample is measured, and the substance is analyzed. A sample holder is filled with a liquid sample containing a substance having a different specific gravity and sealed using a powder X-ray diffractometer having a sample measurement surface parallel to the direction of gravity, and the sample holder is closed three times / second or less (where 0 is This is a method for measuring a liquid sample in which the liquid sample in the sample holder is forcibly agitated to thereby homogenize the liquid sample.

The second invention is a method for measuring a liquid sample, wherein the liquid sample is a ceramic slurry containing ceramic powder.

A third invention is a sample holder for sealing a liquid sample for X-ray diffraction analysis, comprising a container having a concave portion in the center, and an organic film covering an opening surface of the concave portion of the container. And a fixing ring for fixing the organic film to the opening surface of the concave portion of the container.

A fourth invention is a sample holder in which the organic film is made of a polypropylene mylar film.

According to a fifth aspect of the present invention, the sample holder comprises:
This is to be used for a powder X-ray diffractometer in which the sample measurement surface and the direction of gravity are parallel.

According to a sixth aspect of the present invention, there is provided an X-ray diffraction apparatus for irradiating a predetermined sample with X-rays, measuring the intensity of the X-ray diffracted by the sample, and analyzing a substance, wherein an X-ray source unit includes: An X-ray detection unit, a goniometer unit, a first drive unit that rotates the goniometer, a sample holder, a support unit that holds the sample holder, and a second drive unit that rotates the sample holder , The rotation axis of the first drive unit and the second
Are X-ray diffraction apparatuses in which the rotation axes of the driving units are orthogonal to each other.

According to a seventh aspect of the present invention, the sample holder used in the X-ray diffractometer has a container having a concave portion at the center, an organic film covering an opening surface of the concave portion of the container, and X comprising a fixing ring fixed to the opening surface of the concave portion of
It is a line diffraction device.

According to an eighth aspect of the present invention, the sample holder comprises:
The X-ray diffractometer rotates at a rotation speed of 3 times / second or less (excluding 0).

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A measuring method, a sample holder and an apparatus according to the present invention will be described below with reference to the drawings. FIG.
It is a figure which shows the sample holder of this invention, (a) is an exploded perspective view, (b) is an external appearance perspective view at the time of a measurement, (c) is an enlarged sectional view in the AA line of (b). The sample holder 1
A container 2 having a recess 2a in the center, an organic film 3 covering the opening surface of the recess 2a, and the organic film 3
and a fixing ring 4 to be fixed to the opening surface of FIG.

The container 2 has holes 2b and 2c. The hole 2b is a hole for injecting the liquid sample 6, and the hole 2c is a hole for removing air from the concave portion 2a when the liquid sample 6 is injected. The hole 2b for injecting the liquid sample 6 and the hole 2c for removing air may be used in reverse. The holes 2b and 2c are provided with plugs 5 during X-ray diffraction measurement.
b, 5c to prevent leakage of the liquid sample 6,
The recess 2a is a closed space. The stopper 5b,
5c fits into the holes 2b and 2c of the container 2,
The material is made of oil-based clay or the like, organic rubber, metal or the like. The shape may be a lump or a screw as long as it fits. The organic film 3 is made of a mylar film of a polypropylene film, and can be formed freely along the container 2 and the fixing ring 4. The organic film 3
Indicates that the X-ray absorption is relatively small, the sensitivity is not reduced, and the accuracy of the measured value is not reduced. The container 2 and the fixing ring 4 are made of aluminum, and have a structure fitted with the organic film 3 interposed therebetween.

FIGS. 2A and 2B are configuration diagrams showing the X-ray diffraction apparatus of the present invention, wherein FIG. 2A is a layout view showing an optical system, and FIG. The X-ray diffractometer of FIG. 2 irradiates a sample 6 of a sample measuring unit 10 after an incident X-ray 8 emitted from an X-ray source unit 7 for generating X-rays passes through an entrance slit 9, and is diffracted by the sample 6. Diffraction X
The line 11 is detected by the detection unit 13 via the light receiving slit 12. The diffracted X-rays 11 detected by the detection unit 13 are converted into electric signals, processed by a computer (not shown), and displayed as an X-ray diffraction pattern.

The sample measuring section 10 comprises a sample holder 1, a sample holder supporting section 14, a sample holder driving section 15, a goniometer 17, and a goniometer driving section 18. Sample holder 1
Is connected to a mandrel 15 a from the sample holder driving unit 15, and is rotated about the rotation shaft 16 in accordance with the rotation of the driving unit 15.
It is rotated at a speed of less than times / second. Also, the sample holder 1
Is supported by a sample holder support 14, and the sample holder support 14 is mounted on the center of the goniometer 17 by the mandrel 14 a of the sample holder support 14.
The goniometer 17 is rotated by a goniometer driving section 18 about a rotation axis 19 so as to be in a diffraction angle range of 0 to 2θ.

A liquid sample 6 containing a substance having a different specific gravity is injected from the hole 2b of the sample holder 1 into the concave portion 2a, and is continuously injected until the liquid sample 6 comes out of the hole 2c. After filling the concave portion 2a with the liquid sample 6, the holes 2b and 2c are closed with plugs 5b and 5c.
To prevent the liquid sample 6 from leaking from the concave portion 2a. The sample holder 1 filled with the liquid sample 6 is fixed to the sample holder supporting portion 14 of the X-ray diffraction apparatus, and is irradiated with X-rays while rotating the sample holder 1 at three times / second or less.
The diffraction X-ray 11 of the liquid sample 6 obtained therefrom was measured,
Obtain an X-ray diffraction pattern.

Using the sample holder and the X-ray diffractometer,
The following experiment was performed. (Example 1) 80 g of neodymium oxide was mixed with 160 ml of pure water to form a slurry, and the slurry was heated to 70 ° C. 70 ° C
The reaction time was changed from 0 to 40 minutes, the sample was filled in a sample holder, and the change in the X-ray diffraction pattern due to the change in the reaction time was measured while rotating the sample holder at a rotation speed of once / second. did. FIG. 3 is a diagram showing the change over time of the X-ray diffraction pattern in the hydroxylation reaction of neodymium oxide. The solid line is immediately after the reaction, the dotted line is after 10 minutes, the dashed line is after 20 minutes, and the dashed line is after 30 minutes. The dotted line shows the X-ray diffraction pattern after 40 minutes. As the reaction time changes, Nd ₂
It can be seen that the O ₃ peak becomes lower and the Nd (OH) ₃ peak appears, and the change with time can be captured every hour.

(Embodiment 2) BaTi having a relatively large specific gravity
X-ray diffraction of a slurry in which 25 g of O ₃ powder was dispersed in 50 ml of pure water was measured using the same sample holder and X-ray diffractometer as in Example 1. When the sample holder is rotated once / second and when the sample holder is not rotated, BaTiO ₃ (111) is used.
As a result of comparing the P / B (peak intensity / background intensity) ratio of the surface, when rotated once / second, P / B = 5.
In contrast to 5, when not rotating, P / B =
2.5. The difference of about twice the P / B ratio between the case where the sample holder is rotated and the case where the sample holder is not rotated is as follows.
If the sample holder is not rotated, the BaTiO ₃ powder will settle down, the diffraction line intensity of BaTiO ₃ will decrease, and the P / B ratio will decrease due to an increase in the background due to water. BaTiO during measurement
_{This is because 3} is uniformly dispersed and the diffraction line intensity of BaTiO ₃ appears strongly.

Using the slurry, the change in the X-ray diffraction pattern due to the difference in the number of rotations was measured. Figure 4 is a graph showing the change in X-ray diffraction pattern of the rotation speed difference of the sample holder, BaTiO ₃ (110) (10
1) The peak intensity of the plane was measured. The solid line is 0 times / second, the dotted line is 2 times / second, the broken line is 3 times / second, and the dashed line is 4 times / second.
2 shows a line diffraction pattern. As shown in FIG. 4, when there is no rotation, the BaTiO ₃ powder in the slurry sediments,
Although the peak intensity of the O ₃ (110) (101) plane decreases and becomes a broad peak, when there is rotation, the slurry is homogenized and BaTiO ₃ (110) (101)
A sharp peak is obtained with a high peak intensity on the surface. 4
When the rotation speed is higher than that, the BaTiO ₃ powder and the water are easily separated, and the peak is broad. If the rotation speed is high, phase separation occurs on the same principle as centrifugation.
In a slurry containing aTiO ₃ , the optimal rotation condition is 3 times / second or less.

(Example 3) Titanium oxide (Anatase) 50
g was mixed with 100 ml of pure water for 6 hours, and the slurry was measured by rotating the sample holder once / second using the same sample holder and X-ray diffractometer as in Example 1. Titanium oxide (20
The diffraction line intensity of the 0) plane was measured. D calculated from the diffraction angle
Table 1 shows the values and the diffraction intensities.

[0024]

[Table 1]

The d value indicates the accuracy of the angle of the jig, and the strength indicates the accuracy of the measuring method. The use of the X-ray diffractometer of the present invention has a high angle reproducibility, and the variation in intensity is within the range of no error compared with the statistical fluctuation error. You can see that it is.

FIG. 5 is a view showing another embodiment of the sample holder according to the present invention, wherein (a) is a perspective view at the time of measurement,
(B) is an enlarged sectional view taken on line BB of (a). The sample holder 21 includes a container 22 having a concave portion 22a at the center.
And an organic film 23 covering the opening surface of the concave portion 22a, and a fixing ring 24 for fixing the organic film 23 to the opening surface of the concave portion 22a of the container 22.

The organic film 23 is formed of a mylar film of a polypropylene film, and can be formed freely along the container 22 and the fixing ring 24. The container 22 and the fixing ring 24 are made of aluminum, and have a structure in which they are fitted with the organic film 23 interposed therebetween. A hole is not provided in the container 22 of the sample holder 21 according to the different embodiment, but a hole may be provided as in the above-described embodiment.

Further, the container 2 of the sample holder 1 of the embodiment need not be provided with a hole unlike the sample holder 21 of the different embodiment. Furthermore, the organic films 3 and 23 use a Mylar film of a polypropylene film, but a film of polyimide, polyetherimide, or polyetheretherketone may be used as long as the film does not cause a decrease in X-ray sensitivity.
Although the containers 2 and 22 and the fixing rings 4 and 24 of the sample holders 1 and 21 are made of aluminum, they may be made of metal such as stainless steel or plastic such as polyethylene. Furthermore, it is better to determine the rotation number of the sample holder by determining the optimum condition within the range of 3 times / second or less according to the composition, viscosity and concentration of the measurement sample.

[0029]

According to the method for measuring a liquid sample of the present invention, phase separation due to a difference in specific gravity of a liquid sample containing substances having different specific gravities can be prevented, measurement can be performed in a homogenized state, and measurement accuracy can be improved. In addition, the steps of drying and evaporating the liquid sample can be omitted, the measurement time can be shortened, the reaction promoted in the drying and evaporating steps and the change of the crystal state between the liquid and the powder are eliminated, and the accurate crystal state is obtained. Can be evaluated. Further, since the steps of drying and evaporating the ceramic slurry can be omitted, the distortion of the crystal during grinding can be measured quickly, the grinding time can be determined quickly, and the analysis period can be shortened.

Next, in the sample holder of the present invention, the measurement surface of the sample holder is covered with an organic film, and the liquid sample can be sealed and measured. Further, the organic film has a low X-ray absorption coefficient and a low X-ray absorption coefficient.
Since a Mylar film of polypropylene having good line transmission is used, the influence at the time of measurement can be reduced. Further, it can be used for a conventional powder X-ray diffraction apparatus.

Further, the X-ray diffraction apparatus according to the present invention can rotate the sample holder at a low speed. In addition, since the sample holder is rotated, the liquid sample is stirred, phase separation caused by a difference in specific gravity is prevented, and measurement accuracy can be improved. Further, the steps of drying and evaporating the liquid sample can be omitted, and accurate evaluation in the liquid state can be performed.

[Brief description of the drawings]

FIG. 1 is a view showing a sample holder of the present invention;
Is an exploded perspective view, (b) is an external perspective view at the time of measurement, and (c) is an enlarged cross-sectional view taken along line AA of (b).

FIG. 2 is a configuration diagram showing an X-ray diffraction apparatus according to the present invention;
(A) is an arrangement view showing an optical system, and (b) is an enlarged side view of a sample measurement portion of (a).

FIG. 3 is a diagram showing a change over time of an X-ray diffraction pattern in a hydroxylation reaction of neodymium oxide.

FIG. 4 is a diagram showing a change in an X-ray diffraction pattern depending on a difference in rotation speed of a sample holder.

5A and 5B show different embodiments of the sample holder of the present invention, wherein FIG. 5A is an external perspective view at the time of measurement, and FIG.
It is an expanded sectional view in the -B line.

FIG. 6 is an external perspective view of a conventional sample holder for X-ray analysis during measurement.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sample holder 2 Container 2a Depression 2b, 2c Hole 3 Organic film 4 Fixing ring 7 X-ray source part 10 Sample measurement part 13 X-ray detection part 14 Sample holder support part 15 Sample holder drive part 16 Rotation axis of sample holder drive part 17 Goniometer 18 Goniometer drive unit 19 Rotation axis of goniometer 21 Sample holder 22 Container 22a Depression 23 Organic film 24 Fixing ring

Claims (8)

[Claims] An X-ray diffraction method for irradiating a predetermined sample with X-rays and measuring the intensity of X-rays diffracted by the sample to analyze a substance.
A sample holder is filled with a liquid sample containing substances having different specific gravities by using a X-ray diffractometer, and the sample holder is closed three times.
A method for measuring a liquid sample, comprising rotating the liquid sample in the sample holder forcibly by rotating the liquid sample at a rotation speed of seconds or less (excluding 0), thereby homogenizing the liquid sample. 2. The method according to claim 1, wherein the liquid sample is a ceramic slurry containing a ceramic powder. 3. A sample holder for sealing a liquid sample for X-ray diffraction analysis, comprising: a container having a concave portion in a central portion; an organic film covering an opening surface of the concave portion of the container; A sample holder, comprising: a fixing ring fixed to an opening surface of the concave portion of the container. 4. The sample holder according to claim 3, wherein the organic film is made of a mylar film of polypropylene. 5. The sample holder according to claim 3, wherein the sample holder is used for a powder X-ray diffractometer in which a sample measurement surface and a direction of gravity are parallel. 6. X-ray diffraction for irradiating a predetermined sample with X-rays, measuring the intensity of X-rays diffracted by the sample, and analyzing a substance, wherein an X-ray source unit, an X-ray detection unit, A first driving unit that rotates the goniometer, a first driving unit that rotates the goniometer, a sample holder, a support unit that holds the sample holder, and a second driving unit that rotates the sample holder. An X-ray diffraction apparatus, wherein a rotation axis of the unit and a rotation axis of the second drive unit are orthogonal to each other. 7. A sample holder used in the X-ray diffractometer, a container having a concave portion at a central portion, an organic film covering an opening surface of the concave portion of the container, and fixing the organic film to a concave opening surface of the container. 7. The X-ray diffraction apparatus according to claim 6, comprising a fixing ring. 8. The X-ray diffraction apparatus according to claim 6, wherein the sample holder is rotated at a rotation speed of 3 times / second or less (however, excluding 0).