Thermal and Magnetic Properties of Praseodymium Ethylsulphate Below

摘要

Single crystals of praseodymium ethylsulphate have been cooled below 1°K by adiabatic demagnetization and the sus¬ceptibility, expressed in terms of the magnetic temperature T, wad measured as a function of T using cerium magnesium nitrate as a thermometer. The specific heat was measured by electrical heating of the sample. A systematic departure of the susceptibility from Curie's law and an anomaly in the specific heat were found. The results were interpreted and confirmed the existence of a variable splitting of the ground doublet, as predicted from para¬magnetic resonance experiments, with a root-mean-square value of △o = (0.53 ±0.04)°K, which is much larger than the one in the diluted salt.