Magnetic measurements at pressures above 10 GPa in a miniature ceramic anvil cell for a superconducting quantum interference device magnetometer

摘要

A miniature ceramic anvil high pressure cell (mCAC) was earlier designed byus for magnetic measurements at pressures up to 7.6 GPa in a commercialsuperconducting quantum interference (SQUID) magnetometer [N. Tateiwa et al.,Rev. Sci. Instrum. 82, 053906 (2011)]. Here, we describe methods to generatepressures above 10 GPa in the mCAC. The efficiency of the pressure generationis sharply improved when the Cu-Be gasket is sufficiently preindented. Themaximum pressure for the 0.6 mm culet anvils is 12.6 GPa when the Cu-Be gasketis preindented from the initial thickness of 0.30 to 0.06 mm. The 0.5 mm culetanvils were also tested with a rhenium gasket. The maximum pressure attainablein the mCAC is about 13 GPa. The present cell was used to study YbCu2Si2 whichshows a pressure induced transition from the non-magnetic to magnetic phases at8 GPa. We confirm a ferromagnetic transition from the dc magnetizationmeasurement at high pressure. The mCAC can detect the ferromagnetic orderedstate whose spontaneous magnetic moment is smaller than 1 mB per unit cell. Thehigh sensitivity for magnetic measurements in the mCAC may result from the thesimplicity of cell structure. The present study shows the availability of themCAC for precise magnetic measurements at pressures above 10 GPa.