The Spin-Lattice Relaxation Processes of the Relaxed Excited State of F Centers in KBr

Abstract

The temperature dependence of the spin-lattice relaxation time, T₁^*(T), of the relaxed excited state (RES) of F centers in KBr has been obtained from analysis of the temperature variation of the magnetic circular polarization (MCP) of luminescence, Δ_MCP(T), under the magnetic field of 0.3 T. It was found that 1⁄T₁^*(T) obeys the Raman process (T⁹-dependence) due to phonon modulation of a crystal field above 7 K. From the curve-fitting of Δ_MCP(T), the proportionality constant F_p between the para-magnetic component of the MCP and the spin polarization in the RES has been estimated to be |F_p|<0.01.