CRYSTAL FIELD EFFECTS IN COCL2 6H2O.
Abstract:
The heat capacities of CoCl2, 6H2O and NiCl2, 6H2O have been measured between 13 and 200 K. The heat capacity of the CoCl2, 6H2O lattice has been estimated from the data on the Ni salt using a corresponding states argument and subtracted from the measured total. The remainder is a Schottky anomaly due to the presence of excited Kramers doublets within several hundred reciprocal centimeters of the lowest one. The doublet separations and g-factors of the Co ion in a crystalline field containing cubic, tetragonal and rhombic components have been computed as functions of the field parameters and spin-orbit coupling constant. A consistent interpretation of the thermal data and the principal values of the g-tensor g12.23, g25.13, g34.90 deducted from susceptibility measurements is found to require that the crystalline field contains substantial tetragonal and rhombic components. There is an indication that the spin-orbit coupling constant is smaller than the free ion value. Author