Manganese centers with various valency in alkali halides

Abstract

Abstract Optical absorption bands and epr spectra of NaCl: Mn++ X-irradiated at liquid nitrogen and room temperature are studied. Manganese epr spectra are divided into three classes, based on the value of hyperfme splitting constants. It is shown that the epr spectra with the hyperhe splitting constants of around 250 × 10-4, 80 × 10−4 and 20 × 10−4 cm−1 are caused by Mn+, Mn++ and Mn9, respectively. Formation of several manganese centers by X-irradiation is discussed. It is suggested that optical absorption bands at 410 and 440 nm are caused by MnO at the lattice site and that the MnO center which gives an epr spectrum with A = 15. 5 × 10−4 cm−1 is associated with a Mn0 center which is not at a substitutional site.