E. P. R.‐Studies of V 2 O 5 Single Crystals. II. Defect Centres in Molybdenum‐Doped Vanadium Pentoxide

In Mo‐doped V 2 O 5 a paramagnetic defect is formed, in which the unpaired spin interacts with only one vanadium nucleus. Two non‐equivalent centres are present per unit cell. Both have the c ‐axis as the principal axis of the g ‐and hyperfine tensor, whereas one of the other axes forms an angle of ±7° with b ‐axis. The results are summarized by an orthorhombic spin‐Hamiltonian with\documentclass{article}\pagestyle{empty}\begin{document}$$ \begin{array}{*{20}c} {g_x = 1.905 \pm 0.001,} & {A_x = (158.5 \pm 0.5){\rm G},} \\ {g_y = 1.981 \pm 0.001,} & {A_y = (52.8 \pm 0.5){\rm G},} \\ {g_x = 1.977 \pm 0.001,} & {A_z = (50.8 \pm 0.5){\rm G}.} \\ \end{array} $$\end{document} Some possible models are discussed.