Micromagnetic susceptometer

Abstract

A variable temperature (4.2 K to 300 K) micromagnetic susceptometer has been designed to maximize sensitivity to the magnetic flux produced by small samples. The susceptometer is based upon a superconductive flux sensor which measures the magnetic flux through a set of coils due to a sample magnetized in a uniform field. A minimum measurable volume susceptibility of 7.5 ×10−8 (emu) for a 1 microgram sample of curium has been achieved giving an increase in sensitivity of two orders of magnitude over Faraday devices designed for microgram metallic samples.