Spin Resonance of SnO2:V and the Vanadium 3d Electron Orbital

The ESR spectrum of SnO2 containing about 0.5% vanadium observed in K band at liquid-nitrogen temperature shows two sets of shfs. Relative intensity measurements show that the large shfs (168 G) is due to the two tins located along the c axis and the small shfs (28 G) due to the four tins lying in a diagonal plane of the unit cell containing four oxygens. The large shfs is largely isotropic, with an axial maximum along the c axis. This suggests that the ground electron level is 3d(x2−y2). The next level is 3d(xz). This is deduced from the g values (gxx=1.939,gyy=1.903,and gzz=1.943).