Optical and Thermal Conversion of V_k Centers in X-Irradiated Hydroxylammonium Chloride

Abstract

The Cl₂⁻ centers trapped in X-irradiated single crystals of hydroxylammonium chloride have been studied by electron spin resonance technique in the temperature range from 77°K to 150°K. Two crystallographically inequivallent Cl₂⁻ centers designated as V_k(I) and V_k(II) are produced in the crystal. The former is composed of a chlorine ion pair situated on the bc plane and the latter is formed from a pair on the plane nearly perpendicular to the bc plane. Thermal conversion from V_k(I) into V_k(II) takes place thermally above 105°K and V_k(II) is converted into V_k(I) by irradiation with the V_k light at 77°K.