Superconducting magnetometer for high resolution susceptibility measurements

A superconducting susceptometer operating in temperature range up to 2300K was developed. The instrument is capable of routine susceptibility measurements on frozen solutions and suspensions, powders, and crystals. A single helium fill-up lasts about 8 hours and allows about 50 susceptibility measurements at various sample temperatures. Sensitivity is 6 x 10-11 e.m.u./cc for a sample volume of 0.5 cc and is independent of temperature. The overall accuracy of the instrument for sample temperatures up to 2300K is 3 x 10-9 e.m.u./cc, temperature independent, in a typical applied field of 20 gauss