Solid-Liquid Phase Diagrams of 3He in Porous Glasses

Abstract

Solidification and melting phenomena of 3He in restricted geometries were investigated by measuring the magnetization, Mz, and the spin lattice relaxation time, T1 of 3He with SQUID-NMR technique. Two porous glasses were used whose average pore diameters were 4 nm and 18 nm, respectively. Measurements were made at various pressures between S.V.P. and 9 MPa in the temperature range between 20 mK and 4 K. The melting curve minimum in the P-T phase diagram was observed for 18 nm porous glass, but not for 4 nm. We attributed this to the depression of Fermi temperature, in addition to the large hysteresis between solidification and melting, for 3He in the small pores.