Long range superhyperfine interactions in polycrystalline vanadium doped SnO2 investigated by CW and pulsed ENDOR spectroscopy

CW and pulsed ENDOR was used to probe the electron nuclear superhyperfine interactions between V4+ ions and distant Sn nuclei in vanadium doped tin oxide (V/SnO2). Whilst interactions with two sets of nearest neighbour Sn nuclei (with a V–Sn distance of 3.185 and 3.708 Å respectively) are observed by EPR, superhyperfine couplings to two remote sets of tins (with a V–Sn distance of 6.370 and ∼7.42 Å) are detected by ENDOR. The interaction was found to be largely isotropic and largest along the crystal c axis. Small differences in the remote tin environments were also detected by ENDOR.