Device for measuring high temperature and high pressure transport properties based on diamond opposed anvils

Abstract

The invention discloses a device for measuring high temperature and high pressure transport properties based on diamond opposed anvils, and belongs to the technical field of physical quantity in-situmeasuring device under extreme conditions. The device comprises a press machine upper die (1), a press machine lower die (11), and diamond anvil cells (2); a metal gasket (6) is clamped between the two diamond anvil cells, and two diamond anvil cells are fixed on a support block (4) and a rocking bed (5) respectively; a rocking bed base (7) is placed at the bottom of the rocking bed, and a rockingbed cover (8) is placed at the upper part of the rocking bed; mica pieces (9) are placed between the support block and a press machine, and between the rocking bed base and the press machine respectively; a prepared ceramic die (3) is fixed in a step trough of the support block, and a ceramic die (13) sleeves the rocking bed. A sample (10) is guaranteed to be in a high temperature and high pressure environment, on the basis of easy operation and overcoming of the damage of high temperature on the press machine and the loss of pressure due to high temperature, the high temperature and high pressure transport properties of the sample are measured, and favorable conditions are provided for in-situ measurement of multiple physical quantities under the extreme conditions.

Description

technical field [0001] The invention belongs to the technical field of in-situ measuring devices for physical quantities under extreme conditions, and in particular relates to a device for measuring high-temperature and high-voltage electrical transport and heat transport properties in a diamond anvil. Background technique [0002] Diamond Anvil Cell (DAC for short) is currently the only scientific device that can generate a static pressure of one million atmospheres, and is the most important scientific instrument in the field of high-pressure science and technology research. Using two specially-made diamond anvils, the known pressure limit has exceeded 1TPa. If combined with high-temperature technology, the temperature and pressure environment simulated in the laboratory can completely study the physical and chemical properties of related substances in the earth's interior, which is the key to explain seismic wave data. , An important way to understand the internal structu...

AI Technical Summary

Problems solved by technology

However, there are huge technical difficulties in how to detect the changes of pressure and temperature on the transport properties of materials in real time. The main reason is that the relevant experimental techniques for in-situ testing under high temperature and high pressure are very complicated. Technological Breakthrough of Anvil Device Improvement

[0003] So far, the pressure generation and calibration technology under extreme conditions has been very mature, but due to high-temperature oxidation of the diamond anvil, high-temperature damage to the diamond anvil press, etc., the temperature range of the experiment is limited, resulting in the sample in the DAC. The heating problem has not been well resolved

However, the above three methods have their own defects that limit their use: the first method uses strong laser pulses to heat the sample, and the introduction of heat-insulating and pressure-transmitting media restricts part of the electrical and heat transport. Measurement of transport properties

In addition, because this method uses black body radiation to measure temperature, it not only has high requirements for experimental equipment, but also has a large temperature measurement error. The temperature measurement error of this method can reach about 50K above 1500K, and the temperature measurement error is even greater below 1500K.

In the second and third methods, the deformation caused by the high temperature of the press will cause damage to the press, the pressure disc spring will soften at high temperature, resulting in pressure loss, and the diamond anvil exposed to the air will face the problem of oxidation , thus limiting the temperature range of the experiment

[0004] In order to solve the damage to the press and the loss of pressure caused by the high temperature environment, the applicant's patent "Internal Cooling Diamond Counter Anvil Press" (Patent No.: 201510036364.X) discloses a diamond counter anvil press with built-in water cooling. During the high-temperature experiment, the press body can be guaranteed to be at room temperature, which basically solves the problems of high-temperature damage and pressure loss of the press. However, the experimental temperature is still limited due to the failure to solve the problem of diamond anvil oxidation.

The inner-cooled diamond-anvil press adopts a sleeve-type design, and the arrangement and operation of electrodes and thermocouples are relatively difficult; due to the remarkable cooling effect of the press, most of the heat is consumed, so the heating wire requires higher power, reducing However, the heating space is still limited; in order to solve the problem of temperature limitation, a mica sheet is placed between the support block and the press, which limits the accuracy of leveling and alignment; the heating wire is wound on the support On the upper surface of the block or the gasket, less effective heat is transferred to the sample, and more heat is dissipated in the form of air heat conduction, heat convection, and heat radiation

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