Miniature ceramic-anvil high-pressure cell for magnetic measurements in a commercial superconducting quantum interference device magnetometer

摘要

A miniature opposed-anvil high-pressure cell has been developed for magneticmeasurement in a commercial superconducting quantum interference device (SQUID)magnetometer. Non-magnetic anvils made of composite ceramic material were usedto generate high-pressure with a Cu-Be gasket. We have examined anvils withdifferent culet sizes (1.8, 1.6, 1.4, 1.2, 1.0, 0.8 and 0.6 mm). The pressuregenerated at low temperature was determined by the pressure dependence of thesuperconducting transition of lead (Pb). The maximum pressure $P_{max}$ dependson the culet size of the anvil: the values of $P_{max}$ are 2.4 and 7.6 GPa for1.8 and 0.6 mm culet anvils, respectively. We revealed that the compositeceramic anvil has potential to generate high pressure above 5 GPa. Thebackground magnetization of the Cu-Be gasket is generally two orders ofmagnitude smaller than the Ni-Cr-Al gasket for the indenter cell. The presentcell can be used not only with ferromagnetic and superconducting materials withlarge magnetization but also with antiferromagnetic compounds with smallermagnetization. The production cost of the present pressure cell is about onetenth of that of a diamond anvil cell. The anvil alignment mechanism is notnecessary in the present pressure cell because of the strong fracture toughness(6.5 MPa${\cdot}$m$^{1/2}$) of the composite ceramic anvil. The simplifiedpressure cell is easy-to-use for researchers who are not familiar with highpressure technology. Representative results on the magnetization ofsuperconducting MgB$_2$ and antiferromagnet CePd$_5$Al$_2$ are reported.