Apparatus for Measuring Magnetothermodynamic Properties to High Fields at Low Temperatures

Abstract

An apparatus has been described for determining magnetothermodynamic properties at any accessible low temperatures and at any obtainable static or slowly varying magnetic fields. It is adapted to measurements on single crystals in various axial directions. It has been devised to give values of the magnetic susceptibility and intensity of magnetization as a function of field or temperature along isothermal or isoerstedic paths, and thus evaluates the magnetic work functions of the substance measured. With appropriate adjustments, values of the isothermal entropy change may be determined calorimetrically as a function of field, or values of heat capacity at constant field may be measured. Below 1 °K the various magnetothermodynamic changes accompanying adiabatic demagnetization may be evaluated. Itemized dependences of error limits are given.