Precise pressure-temperature control system for electrical measurements down to 4.2 K using helium gas as a pressure transmitting medium

A system in which electric measurements can be performed under a good hydrostatic condition (up to 7 kbar in helium gas environment) and under very precisely controlled temperature has been developed. This system is especially suitable for the very low temperature measurements (down to 4.2 K) where most pressure transmitting materials solidify. The system has been utilized for the measurements of dielectric constant and the spontaneous polarization of a quantum ferroelectric, tris-sarcosine calcium bromide ((CH 3 NHCH 2 COOH) 3 CaBr 2 ; TSCB).