Spin Resonance of Pd and Pt in Silicon

The transition metals Pd and Pt usually occur in diamagnetic form. However, in silicon both Pd and Pt act as acceptor impurities; the ions Pd^- and Pt^- are paramagnetic and have been studied by electron spin resonance. Both ions have a [001] and two mutually perpendicular [110] axes as principal axes of the g tensor. Hyperfine interaction with Pd¹⁰⁵, and Si²⁹ has been detected and studied. In particular, Pd¹⁰⁵ shows a strong quadrupolar interaction. The spectra are discussed in terms of models in which the ions are distorted from the normal substitutional site along a cubic direction. A second spectrum, which may represent a defect pair, has been observed for Pt.