Jahn-Teller and Reorientation Effects in the ESR Spectrum of the Self-Trapped Holes in Mixed Crystals AgBr1-xClx. II

Abstract

Electron spin resonance study shows that holes in AgBr 0.001 Cl 0.999 crystal are self-trapped as the complexes (AgBrCl 5 ) 4- besides the complexes (AgCl 6 ) 4- . The complex (AgBrCl 5 ) 4- has a rhombic symmetry due to a Jahn-Teller effect and to a tetragonal crystal field created by a Br ligand. The energy barrier between two configurations of the complex (AgBrCl 5 ) 4- is estimated to be lower than those between three configurations of the complex (AgCl 6 ) 4- , so that we can expect occurrence of a dynamic or intermediate Jahn-Teller effect for the complex (AgBrCl 5 ) 4- . The ESR line shapes have been calculated for several values of \(2\varGamma/\delta\), which represents the ratio of the tunneling splitting to the random strain splitting. The result shows that the low-temperature ESR spectrum of the complex (AgBrCl 5 ) 4- is associated with an intermediate Jahn-Teller effect.