In-situ temperature measuring thermocouple on diamond anvil cell and preparation method thereof

Abstract

The invention discloses an in-situ temperature measuring thermocouple on a diamond anvil cell and a preparation method thereof, belonging to the technical field of in-situ temperature measuring devices under extreme conditions. A W-Ta thermocouple in the invention has a structure that an alumina barrier (2) is deposited on the surface of a diamond anvil (1); a tungsten film (3) and a tantalum film (4) which are smaller than half of the surface area of the anvil in area are respectively deposited on the alumina barrier (2) to be used as conductors of the thermocouple and are spaced by the alumina barrier (2); the tungsten film (3) and the tantalum film (4) are in overlapped contact at the centre of the anvil surface and used as thermocouple contacts. The W-Ta thermocouple is manufactured on the surface of the diamond anvil (1) through a film manufacturing technology and a photoetching technology. The countercurrent heat transfer change between the W-Ta thermocouple disclosed by the invention and a detected surface is extremely small, the W-Ta thermocouple has extreme little interference to heat conduction on the surface, and is faster to respond to the temperature; moreover, the measured result reflects actual temperature of the measured surface and in-situ temperature measurement under the high temperature and high pressure conditions is realized.

Description

technical field [0001] The invention belongs to the technical field of devices for in-situ temperature measurement under extreme conditions, and in particular relates to a thermocouple for temperature measurement made on a diamond counter-anvil and a preparation method for the thermocouple. Background technique [0002] Diamond Counter Anvil (DAC) is currently the only scientific device capable of generating 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 DAC, people can observe changes in the structure and physical properties of substances in ultra-high pressure environments, especially in the laboratory simulation of the pressure and temperature environment of the deep earth. The laboratory simulates the pressure and temperature environment in the deep part of the earth to study the static physical and chemical properties of related substances in various layer...

AI Technical Summary

Problems solved by technology

So far, the pressure calibration technology under extreme conditions has been very mature, but because the DAC sample cavity is only on the order of hundreds of microns, it is difficult to use ordinary thermocouples in it, so the problem of in-situ temperature measurement in the DAC has not been solved. good solution

The above three methods have their own disadvantages that limit their use: the first method leads to inaccurate measurement because the measurement point cannot directly contact the sample; It is easy to be oxidized and damaged, which limits the use of this temperature measurement method; in the third method, since the sample belongs to a gray body, the temperature measurement error using the black body radiation spectrum is very large

This method is limited to use at temperatures above 2000K. Optical temperature measurement below 2000K is affected by factors such as changes in emissivity, transmission loss, and reflection of ambient rays.

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