An X-band electron paramagnetic resonance study was made of nominally pure diamond-like cubic-phase crystalline powders. This led to the first identification of a spectrum which was attributed to 2 related paramagnetic species. The composite electron paramagnetic resonance spectrum was observed only in dark brown powders which were known to contain an excess of B. It consisted of 2 superposed Lorentzian components, D1 and D2, which were centered at g1 = 2.0063 and g2 = 2.0084; with peak-to-peak linewidths of 3.3 and 17.9mT, respectively. The temperature dependences of the integrated intensities, their linewidths and D2/D1 intensity ratio led to the conclusion that the narrow line, D1, originated from electron paramagnetic resonance transitions within an S = 1/2 ground doublet, and the broad D2 line arose from transitions within the excited levels of another center. The evidence suggested that both centers were B-related paramagnetic species.

EPR Observation of First Point Defects in Cubic Boron Nitride Crystalline Powders S.V.Nistor, M.Stefan, D.Schoemaker, G.Dinca: Solid State Communications, 2000, 115[1], 39-44