Determination of structure factors of disordered vanadium monoxide crystals by the intersecting-Kikuchi-line and critical-voltage methods

The concentration of vanadium atoms at interstitial tetrahedral sites in disordered VO_0.82 and VO_1.20 crystals has been determined by use of both the intersecting-Kikuchi-line method and the critical-voltage method. It is shown that not only the structure factor but also the temperature factor can be determined by combining the two methods. From the structure-factor values obtained, the existence of interstitial vanadium atoms is confirmed for the disordered VO_1.20, supporting the assumption that the defect cluster typical of the ordered phase persists in the disordered state, whereas the interstitial concentration in the disordered VO_0.82 is found to be nearly zero. For VO_1.20 and VO_0.82 the values of 1.21 ± 0.12 and 1.05 ± 0.10 Ų respectively at room temperature were obtained for the B factor which includes contributions from static atom displacements as well as the effect of thermal vibrations.