Mutual Inductance Bridge and Cryostat for Low-Temperature Magnetic Measurements

A mutual inductance bridge and cryostat are described which may be used to measure susceptibilities from 77°K, with liquid nitrogen, down to adiabatic demagnetization temperatures. In addition to the sensitivity necessary for measurements over such a temperature interval, the apparatus provides the following features: a usable frequency range of 5 kc, for the study of paramagnetic relaxation and paramagnetic specific heat; measurement of longitudinal susceptibilities in fields up to 3000 oersted, and transverse susceptibilities in fields up to 13 000 oersted; a simple method for changing samples with a minimum dismantling of the equipment.