51V magic angle spinning NMR in VOPO4 phases

V-51 magic angle spinning NMR was applied to the alpha(II), beta and alpha phases of VOPO4 at three magnetic field strengths (4.7, 7.1, and 11.7 T). The V-51 quadrupole and chemical shift tensors were determined by iterative fitting of the NMR lineshapes at the three magnetic field strengths. The applicability of the method is illustrated by comparison with literature data. Although determined chemical shift tensors are completely axially symmetric and of the same magnitude, all studied phases can clearly be distinguished by their quadrupole coupling tensor. Relationships between the V-51 NMR data and structural characteristics such as crystal symmetries are discussed. Copyright (C) 2004 John Wiley Sons, Ltd.