Muonium states in HgO

Abstract

Experimental data on muonium states in HgO are presented. Muon spin rotation (<em>µ</em>SR) experiments show that, at low temperatures, approximately 80% of muons implanted into a polycrystalline sample form paramagnetic centres with hyperfine interaction parameters <em>A</em>_iso = 14.93(5) MHz and <em>D</em> = 5.2(1) MHz. The remaining 20% form diamagnetic states. Diffusion of the paramagnetic state through equivalent sites is observed above 10 K, averaging the apparent anisotropy to a low value at and above 50 K. The variations of the amplitudes of the two signals with temperature indicate that the paramagnetic centres ionize in a temperature range centred around 160 K and that the associated donor levels lie considerably further from the conduction band edge than the corresponding states in ZnO and other II-VI compounds.