SPIN-LATTICE COUPLING-COEFFICIENTS GIJ FOR TRIGONAL AL2O3-FE3+ AND ZNSIF6.6H2O-NI2+ CRYSTALS2)

By expressing the six spin-lattice coupling coefficients G(ij)t in trigonal symmetry in terms of the coefficients G11c and G44c in cubic symmetry, the coefficients G(if)t for trigonal Al2O3:Fe3+ and ZnSiF6.6H2O:Ni2+ crystals are calculated from the values of G11c and G44c obtained from a simple and uniform method within the framework of cubic symmetry approximation. The results for the Al2O3:Fe3+ crystal is in agreement with the experimental findings, whereas for ZnSiF6.6H2O:Ni2+, the agreement for part of coefficients is poor. The reasons for the disparity are discussed.