Observations on Antiferromagnetic CuCl2·2H2O Crystals

Abstract

Four series of observations carried out in the Kamerlingh Onnes Laboratory on Cu${\mathrm{Cl}}_2$·2${\mathrm{H}}_2$O crystals are reviewed. The magnetization curves confirm the general picture given by the theoretical analysis of Gorter and Haantjes. At the lower temperature a sharp threshold field is found in the crystallographic $\mathrm{ac}$ plane with a minimum value of 6500 φ; at higher temperature its value increases somewhat.