Characterization of Defects in as-Grown CVD Diamond Films and HPHT Diamond Powders by Electron Paramagnetic Resonance

Several defect centers, labeled as KUL1–7, have been detected by electron paramagnetic resonance in CVD diamond films and synthetic diamond powders. Their g values were determined relatively to the P1 (NS0) center, for which the value of g = 2.00216(1) with anisotropy g∥—g⟂ < 0.00003 was determined. Analysis of the hyperfine interaction structure reveals the presence of the following impurities: one hydrogen atom in the centers KUL2–4, one nitrogen atom in the KUL5 and one Mn atom in the KUL7 center. The centers KUL1, 3–6 were observed exclusively in CVD films, KUL7 could only be detected in HPHT powders grown with a Mn–Ni catalyst, while the KUL2 center was found both in CVD and HPHT diamond. Microscopic models for some of the observed centers are discussed.