Reduction of the superfluid fraction of ³he in sintered silver

V. Kotsubo, Cornell University Laboratory of Atomic and Solid State Physics
J. Ditusa, Cornell University Laboratory of Atomic and Solid State Physics
T. Hall, Cornell University Laboratory of Atomic and Solid State Physics
R. Mihailovich, Cornell University Laboratory of Atomic and Solid State Physics
J. M. Parpia, Cornell University Laboratory of Atomic and Solid State Physics

Abstract

We have measured the superfluid density of 3He liquid confined within the pores of a silver sinter plug. The silver was of nominal 70 nm size, and was packed to 54% of solid density. The mean pore size as measured was 蝤200 nm. The plug was mounted on a torsional oscillator, and the superfluid density can be measured by studying the decrease of the resonant period. We have measured the pressure and temperature dependence of the period shift and find that the superfluid density is suppressed to 蝤14% at 0 bar and is 蝤53% of its bulk value at 29 bar. There is substantial temperature dependence even at the lowest values of T/Tc(蝤0.25) achieved in these experiments. © 1987 The Japan Society of Applied Physics.