JPH0325742B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a simultaneous X-ray diffraction thermobalance measurement device that can perform X-ray diffraction analysis and thermal analysis simultaneously.

When investigating the state of a substance's crystals at various temperatures, we use the X-ray diffraction phenomenon that occurs when a substance at each temperature is irradiated with X-rays, and observe this.
An analysis is performed.

In other words, when X-rays of a certain wavelength are incident on a crystal, diffracted X-rays are generated in a direction that satisfies Bragg's diffraction conditions.By measuring the diffraction angle, the lattice spacing of the crystal can be determined, and it is also possible to By irradiating a sample containing a mixture of crystals with X-rays at various incident angles and observing the presence or absence of diffracted X-rays at each angle, it is possible to identify the type of substance or estimate the content. Since an X-ray diffraction device is used to perform such measurements, by changing the temperature of the sample and measuring with the device, it is possible to observe the crystalline state of the sample or changes in the substance at each temperature. Can be done. However, X
Measuring by line diffraction alone can only indirectly tell that the state of the crystal has changed, and it is difficult to determine whether the change is due to a change in only the state without changing the constituent elements of the crystal or whether the constituent elements themselves have changed. It is not possible to determine whether the change has occurred due to decomposition, etc.

Therefore, even if X-ray diffraction measurements are performed at various temperatures, the measurements will be of little meaning unless it is possible to distinguish whether changes in the diffracted X-rays are due to crystal transformation or decomposition.

Therefore, the applicant of this case has filed Utility Model Publication No. 43-29117,
We have already proposed a device with the name ``X-ray diffraction device'' that can simultaneously and continuously observe changes in the X-ray diffraction angle and mass changes of the same sample due to temperature changes. Although the device according to the proposal made the simultaneous analysis possible,
It was found that the device had some problems due to the basic configuration of keeping the sample plane horizontal. This problem is that the surface of the sample that undergoes X-ray diffraction moves slightly up and down due to the vibration of the balance, and cannot be kept in a fixed position.

Therefore, there was a risk that the 2Θ angle in the X-ray diffraction method would be observed with a deviation.

SUMMARY OF THE INVENTION An object of the present invention is to provide an improved simultaneous X-ray diffraction thermobalance measurement device that solves the above-mentioned problems.

In order to achieve the above object, the present invention provides a simultaneous X-ray diffraction thermobalance measurement device, which includes a balance held on a base, a balance suspended from one end of the balance, and a surface of a sample. A furnace body for heating the sample, having a sample holder that holds the sample in parallel with the vertical direction, and a window for horizontally irradiating the surface of the sample held on the sample holder with X-rays from the outside. an X-ray tube that is rotatably held in a horizontal plane around the sample and irradiates the sample with X-rays through the window of the furnace body; , an X-ray detector that detects diffracted X-rays emitted from the sample, and a drive mechanism that rotates the X-ray tube and the detector at a one-to-one speed.

According to the above configuration, even if the balance vibrates up and down,
Since the horizontal position of the surface of the sample remains unchanged and no angular deviation of 2θ occurs, X-ray diffraction and mass change can be measured simultaneously with high precision, and the object of the present invention can be completely achieved.

The present invention will be described in more detail below with reference to the drawings and the like. 1 and 2 are a side view and a plan view of an embodiment of the device according to the invention. FIG. 3 schematically shows the internal structure of the sample heating section and the balance mechanism section.

As shown in FIG. 1, the assembly of the sample heating section 1 and the balance mechanism section 3 is fixedly supported by a main body arm 15 supported by a main body support rod 14 fixed to a table 13. . table 1
3, a θ-θ goniometer 4 is placed directly below the assembly of the heating section 1 and the balance mechanism section 3.
The θ-θ goniometer 4 constitutes a drive mechanism that rotates an X-ray tube and a detection tube for detecting diffracted X-rays, which will be described later, at a 1:1 speed while maintaining a predetermined positional relationship.

A drive motor is provided in the θ-θ goniometer 4 and rotates the table in response to instructions from the outside.

An arm 62 that is integral with a shaft 61 is fixed to one of the turntables of the θ-θ goniometer 4. A roller 12 for rotating on the table 13 is provided at the lower end of the shaft 61.

A θ source arm 6 is fixed to the upper end of the shaft 61, and this arm 6 supports a tube shield 7 containing an X-ray tube that is an X-ray source. A balance weight 8 is provided at the other end of the arm 6 to balance the X-ray source. An arm 51 is fixed to the other turntable of the θ-θ goniometer, and the θ detector arm 5 is fixed to the upper end of this arm.
This θ detector arm 5 supports an X-ray counter 11.

The counter 11 constitutes a detector for detecting diffracted X-rays, and its optical axis is directed toward the center of the sample within the heating section. The X-rays emitted from the tube shield 7 are similarly directed toward the center of the sample, and their respective axes are parallel to the plane of the table 13, that is, in a horizontal plane.

Next, the internal structure of the sample heating section 1 and the balance mechanism section 3 will be explained with reference to FIG.

The balance beam 27 is suspended at a fixed position of the balance mechanism 3 by a suspension band 28a. A U-shaped connecting member is provided at the lower end of the support rod 26, on which the sample holder 25 is provided at the upper end, and the lower side of the U-shaped connecting member is connected to one end of the beam by a suspension band 28b. A permanent magnet 33 is provided below the U-shaped connecting member at a position sandwiched between the control coils 34, and a weight 35 is supported by a weight holder provided below the permanent magnet integrally with the permanent magnet. . At the left end of the balance beam 27 is a lamp 30.
The shutter 31 is placed in a position where it can obstruct the path of the photoelectric element.
is provided. The counterweight 29 is a weight for balancing the left and right sides of the balance beam 27. When the amount of the sample supported by the sample holder 25 changes, the balance of the sample tends to collapse. The displacement is detected by the photoelectric element 32, and a negative feedback control system is configured that performs so-called PID operation, which supplies current to the control coil 34 in a direction to cancel the displacement and always maintains the height of the sample at a constant position. Information based on the weight change of the sample is extracted as the magnitude of the negative feedback current.

As is clear from FIGS. 3 and 4, the sample holder 25 is located at the center of the heating section 1, and is surrounded by a soaking tube 23, a heater 24, and a heat shield tube 22.

The central axis of the balance mechanism is supported vertically, and the central axis of the lowermost cone 9 is aligned with the central axis.

Structure 2 provided around holder 25
2, 23, and 24 are provided with windows through which incident rays from the X-ray tube reach the sample, and windows through which diffracted X-rays reach the detection tube.

Aluminum foil 2a is tied with a band 2b to the outward facing window of the heat shielding tube 22 to isolate the inside of the heating section 1 from the outside air.

To start measurement, the sample is supported on the holder 25, and the balance beam 27 is balanced by adjusting the weight 29, weight 35, etc. The sample is held with its surface parallel to the vertical direction. The central axis of the sample surface is aligned with the aperture 9 mentioned above and the center of the θ-θ goniometer 4 using adjustment screws 10 and 16 (see FIG. 1).

By operating the heater 24 of the heatable part,
As soon as thermal analysis is started, the above θ-
Analysis by X-ray diffraction is performed by operating the θ goniometer 4 and rotating the detector and X-ray source.

In the apparatus according to the present invention, the sample is suspended vertically by the sample holder, so even if the sample moves up and down due to external vibrations, the position of the sample surface remains unchanged relative to the X-ray source and detector. be.

The height of the sample is controlled by PID as mentioned above.
Since this is done through control, in principle the height does not change even if the mass changes. Even if there is a slight response delay in the PID control system, the variation in height due to this is negligible, so as mentioned above, the surface of the sample remains unchanged relative to the X-ray source and detector. Can be done.

As is clear from the above description, the apparatus according to the present invention allows X-ray diffraction and thermobalance measurements to be performed simultaneously at each point of continuous temperature change while keeping the sample surface position substantially immobile, which is better than the conventional apparatus. can obtain a high degree of data.

[Brief explanation of the drawing]

Fig. 1 is a side view showing the external appearance of an embodiment of the measuring device according to the present invention, Fig. 2 is a front view thereof, Fig. 3 is a schematic diagram showing the internal structure of the sample heating section and the balance mechanism section, and Fig. 4 is a schematic diagram showing the internal structure of the sample heating section and the balance mechanism section. FIG. 3 is a developed perspective view for explaining the internal structure of the sample heating section. DESCRIPTION OF SYMBOLS 1... Sample heating section, 2... X-ray window, 3... Balance mechanism section, 4... θ-θ goniometer, 5... θ detector arm, 6... θ source arm, 7...
Tube shield, 8...Balance weight, 9
...Center cone, 10...Axis alignment adjustment screw (main body),
11...X-ray counter (detector), 12...
Colo, 13...Table, 14...Body support rod,
15... Body arm, 16... Axial alignment adjustment screw (gonio), 22... Heat shield cylinder, 23... Soaking cylinder, 2
4... Heater, 25... Sample holder, 26... Support rod, 27... Balance beam, 28... Suspension band, 29... Counterweight, 30... Lamp, 31... Shutter, 32... Photoelectric element , 33
...Permanent magnet, 34...Control coil, 35...Weight.

Claims (1)

[Claims] 1. In an X-ray diffraction thermobalance simultaneous measurement device, a balance held on a base, a sample holder suspended from one end of the balance and holding the surface of the sample parallel to the vertical direction, and a sample holder attached to the sample holder. It has a window for horizontally irradiating the surface of the held sample with X-rays from the outside, and a furnace body for heating the sample; irradiating X-rays through the window of the furnace body;
A ray tube, an X-ray detector that is rotatably held in a horizontal plane around the sample and detects diffracted X-rays emitted from the sample, and the X-ray tube and detector are connected at a one-to-one speed. 1. An X-ray diffraction thermobalance simultaneous measurement device characterized by comprising a rotationally driven drive mechanism.