Spin‐Flopping Relaxation Time in CuCl2·2H2O

The relaxation time associated with the spin‐flopping transition in CuCl2·2H2O has been measured and found to be (0.70±0.15)×10−7 sec at 2.4°K. Our measurements also yield the susceptibility and temperature dependence of the critical field Hc. The rf susceptibility was measured with the applied rf and dc fields parallel to the easy axis (a axis) at Hc. The inductive and resistive components of the critical field susceptibility as a function of frequency, fit dispersion, and dissipation curves with a relaxation parameter of tsf=0.7×10−7 sec. at 2.4°K. Some otherwise strange observations have been explained by a temperature rise due to the dissipation of energy in the crystal through the resistive component of χc. For instance, in the measurement of the change of inductance as a function of H in the vicinity of Hc, the curve is found to display asymmetry about the peak and hysteresis. These effects become more pronounced with increasing power, which is consistent with their being of thermal origin.