MAGNETO-OPTICAL STUDY OF MAGNETIC FIELD DEPENDENCE OF SPIN-LATTICE RELAXATION TIMES IN CaF2: Eu2+

Abstract

The maximum rate at which paramagnetic ions in a crystal lattice can respond to a modulating magnetic field superimposed on a static magnetic field is determined by the characteristic relaxation time of the ions. At low temperatures and nonzero static magnetic field the spin-lattice relaxation time (τ) is the dominant characteristic relaxation time. The influence of τ at low temperatures on the phase and amplitude of the ac Faraday rotation is quantitatively described. Experimental results for Eu2+-doped CaF2 are reported which verify the theoretical concepts and yield τ values at 9°K which vary linearly with the applied static magnetic field.