Instrument for high resolution magnetization measurements at high pressures, high magnetic fields and low temperatures

An instrument has been developed for the first time that makes high resolution magnetization measurements at high pressures, high magnetic fields and low temperatures. The instrument consists of an extraction-type magnetometer, a nonmagnetic high pressure clamp cell and a 20 T superconducting magnet with a He-3 refrigerator and is able to precisely measure the magnetization of weakly magnetic materials. TiCu alloy with 3 wt % Ti is employed as a nonmagnetic material with high mechanical strength for the high pressure clamp cell. This apparatus can be used in the pressure range O less than or equal to P less than or equal to 13 kbar, the field range 0 less than or equal to H less than or equal to 200 kOe and the temperature range 0.5 less than or equal to T less than or equal to 4.2 K. The resolution of the instrument is estimated to be +/-0.002 emu. For demonstrating the ability of the instrument, the experimental results on a heavy fern-Lion antiferromagnet Ce7Ni3 is presented. (C) 1998 American Institute of Physics.