Yan Xiaozhi, Ren Xiangting, He Duanwei
Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 610065, People's Republic of China.
Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, People's Republic of China.
Rev Sci Instrum. 2016 Dec;87(12):125006. doi: 10.1063/1.4973448.
The pressure limit in the large-volume-press (LVP) is increasing, but the in situ pressure calibration in LVP is still not a well resolved problem. The variation of the electrical resistance of the manganin with pressure in a hydrostatic condition is well known and is widely used in the pressure calibration in LVP. However, the hydrostatic pressure condition is hard to be maintained for the unavoidable solidification of the pressure transmitting medium (PTM) with pressure increasing. Moreover, our understanding about the relationship between pressure and manganin's resistance in a solid transmitting medium is still limited. Therefore, it is difficult to calibrate higher pressure using manganin. We measured the electrical resistance of manganin under pressure in pyrophyllite, MgO, and NaCl, respectively. The results show a linear relationship between the resistance and pressure in the same PTM with good reproducibility. In addition, the resistance-pressure relationships of manganin in different PTM are obviously different. So the resistance of manganin in a given solid PTM can be satisfactorily used as a pressure gauge only in the same PTM but cannot be used in other pressure media. Our results make it possible to calibrate higher pressure in a solid pressure transmitting medium in LVP.
大体积压机（LVP）中的压力极限在不断提高，但LVP中的原位压力校准仍是一个尚未得到很好解决的问题。在静水条件下，锰铜的电阻随压力的变化是众所周知的，并且被广泛应用于LVP的压力校准。然而，随着压力升高，由于压力传递介质（PTM）不可避免地固化，静水压力条件难以维持。此外，我们对固体传递介质中压力与锰铜电阻之间关系的了解仍然有限。因此，使用锰铜校准更高的压力很困难。我们分别测量了叶蜡石、氧化镁和氯化钠中压力作用下锰铜的电阻。结果表明，在相同的PTM中，电阻与压力之间呈线性关系，具有良好的可重复性。此外，锰铜在不同PTM中的电阻-压力关系明显不同。因此，给定固体PTM中锰铜的电阻仅在相同的PTM中可以令人满意地用作压力计，而不能用于其他压力介质。我们的结果使得在LVP的固体压力传递介质中校准更高压力成为可能。
