X-ray determination of local atomic displacements around carbon vacancies in NbC1-csingle crystals

Abstract
Integrated X-ray Bragg intensities from NbC1-c single crystals (0.051=0.125+or-0.005 AA were determined. These values are in good agreement with the results of lattice statics calculations and with the results of channelling experiments on similar NbC crystals. The temperature-dependent X-ray diffraction experiments showed a decrease of the thermal vibration amplitudes (u2) of the Nb atoms in NbC1-c with increasing vacancy concentration ( Delta (u2)/ Delta c=-0.005 AA2).