Oscillating sample superconducting magnetometer

An oscillating sample version of the superconducting magnetometer has been developed which measures the volume susceptibility of water solutions. Changes in susceptibility as small as 0.3% of the diamagnetism of water, or 2×10−9 cgs, have been resolved in the same run over the temperature range between 30 K and room temperature on magnetically dilute solution samples of 0.1 cm3 volume. The reproducibility of the instrument between different runs in measuring the absolute value of the magnetic susceptibility is 2% of the diamagnetism of water, or 1.5×10−8 cgs. By the combined use of the present method and the previous version it has been possible to measure the temperature dependence of the molar density of ice between 150 K and the melting point.