ESR OF NI2+ IN AGCL AND ISOTOPE EFFECT IN CRYSTAL FIELD

ESR measurements are made on Ni‐doped AgCl at low temperatures. As in the case of AgBr:Ni, already investigated, a line with isotropic g‐value is found, due to isolated Ni2+. Moreover an angular dependent spectrum with nearly [100]‐axial symmetry is observed, which is attributed to complexes of Ni2+ with a silver vacancy. Contrary to the results on AgBr:Ni a structure of the anisotropic spectrum is observed in a small angular range, which may be explained only by the presence of very small orthorhombic perturbations. It is shown, that these orthorhombic perturbations of different quantities result from the variant distributions of both the isotopes 35Cl and 37Cl in the plane perpendicular to the axis of the centre. Copyright © 1969 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim