Paramagnetic resonance absorption of Mn ++ in single crystals of zincblende

Abstract

The anisotropy of the paramagnetic absorption spectrum of manganous ion in a natural crystal of cubic zinc sulfide has been found to be unusually pronounced. The maximum width of an hfs group is 45 gauss with the densities of the components approximately in the ratio 8: 5: 9: 5: 8. This pattern of density distribution is to be expected when quartic terms in the crystalline electric field predominate. The spectra wereobtained at fields in the vicinity of 8500 gauss and at a microwave frequency of approximately 24,000 Mc/sec. The angular dependence was investigated by varying the direction of the magnetic field in the (100), (110) and (111) planes of the crystal. Experimental results indicate that the symmetry of the crystalline electric field about the Mn ++ ion is cubic. The cubic anisotropy constant a is −1.39 gauss, the sign being determined from the dependence of the hfs pattern upon the nuclear magnetic quantum number. The hyperfine interaction constant A is 68.4 gauss. A doublet structure is predicted for the spectrum of manganous ion in hexagonal zinc sulfide.