Characterization of epitaxially grown ZnS:Mn films on a GaAs(100) substrate prepared by the hot-wall epitaxy technique

Abstract

Epitaxially grown ZnS:Mn films on a GaAs(100) substrate prepared by a hot-wall epitaxy technique have been studied using electron paramagnetic resonance (EPR) spectroscopy. The lowest-energy transition assigned to M_l=–5/2 splits into either a triplet or a quintet depending on the thickness of the film when the magnetic field is applied normal to it. Computer simulation confirmed that the EPR parameters obtained correspond to those for a single crystal of cubic structure, although the apparent lineshape is different. There is no significant difference between the hyperfine coupling constants and splitting parameters. The apparent difference in the EPR lineshape is ascribed to the change in linewidths of the fine structure involved. In particular, linewidths for the transitions M_s=±5/2 ⇌±3/2 decrease markedly with increasing thickness of the ZnS:Mn film on the GaAs(100) substrate, confirming that uniaxial deformation of the crystal field surrounding manganese(II) is derived from the lattice mismatch between them.