A new muonium trap in nitrogen-rich diamond discovered by μSR

Abstract

We recently reported on the discovery of a new muonium configuration, Mu X , in nitrogen-rich diamond. The Mu X , observed in combined transverse and longitudinal field muon spin relaxation or rotation measurements during an effort to trace the origin of the large missing fraction peculiar to nitrogen-rich diamonds, was found to have less than axial symmetry. Results of the quantitative analysis confirming the less than axial symmetry of the site are presented. In addition, results of molecular orbital calculations which indicate possible identifications of Mu X within aggregated nitrogen centres are presented. The muon(ium) would be more deeply trapped within the nitrogen-related configurations than in the bond-centered configuration. These nitrogen-related traps are deeper for the muon than for muonium. Indeed, a T1 relaxation of the diamagnetic component is observed for the first time in this data.