Crystallographic polarity of ideomorphic faces on a cubic boron nitride single crystal determined by Rutherford backscattering spectroscopy

The crystallographic polarity of ideomorphic {111} faces appearing on a cubic boron nitride (c-BN) single crystal grown with a temperature gradient method under an ultrahigh pressure of ≅ 55 kbar at a high temperature of ≅ 1800degC has been successfully determined with channeling experiments in Rutherford backscattering spectroscopy (RBS). Other methods such as the X-ray anomalous dispersion method are not applicable for this purpose because boron and nitrogen are light elements with atomic numbers close to each other. It has also been found with particle-induced X-ray emission (PIXE) that the c-BN single crystal contains molybdenum as an impurity (990 ppm), which is thought to have come from a molybdenum cell used in the temperature gradient method for growing the c-BN single crystal. The molybdenum atoms are not at specific lattice sites but at random sites. (orig.)