ESR Studies of Different Se Centres in Silver Halides

Abstract

Abstract The ESR spectrum of AgBr:Se crystals which have been irradiated at 120 °K with green light is changed by heating the crystals to 170 °K. The spectrum obtained after heating was recently investigated and attributed to a Se centre. In the present paper the spectrum observed before heating is analyzed with regard to g ‐values, and superhyperfine and hyperfine structure. This spectrum is also found to be due to a Se centre of ortho‐ rhombic symmetry The two centres differ in their surroundings and a model of this situation is developed. The investigations are extended to AgCl:Se.