Structure of defects in semiconductor crystalline cubic boron nitride. A microstructural and micro analytical investigation

• Published in: Radiation measurements 2019-04, Vol.123, p.78-82
• Main Authors: Nistor, L.C., Vlaicu, A.M., Nistor, S.V.
• Format: Article
• Language: English
• Subjects: Analytical high resolution transmission electron microscopy; Cubic boron nitride; Electron energy loss spectroscopy; Energy dispersive X-ray spectroscopy; Impurities; Scanning electron microscopy
• ISSN: 1350-4487; 1879-0925
• DOI: 10.1016/j.radmeas.2019.02.019

Previous electron spin resonance investigations correlated with data from cathodoluminscence and photoluminescence measurements have shown that impurity ions consisting mainly of isotopes with zero nuclear moments are involved in the structure of the observed paramagnetic point defects. In the present microstructural and compositional investigation we demonstrate that oxygen, carbon and silicon impurity atoms exhibiting low natural content of isotopes with non-zero nuclear spin are indeed present in cBN crystallites selected from amber coloured BORAZON CBN400 and CBN 500 super abrasive powders, as well as in the black coloured BORAZON CBN1000 and CBN Type 1. It is also shown that aggregates of impurity atoms are present next to the extended cBN lattice defects, which could explain the non-uniform distribution of the electro- and opto-active impurities reported in a spectroscopy investigation. •cBN crystals contain extended defects such as dislocations, stacking faults and twins.•The nature and distribution of impurities in cBN crystals is revealed by EDS and EELS.•Oxygen, silicon and carbon impurities are not uniformly distributed in cBN crystals.•The detected impurities can agglomerate at extended defects or form precipitates.