Electron Spin Resonance of V4+(VO2+) in Beryl

Abstract

Synthetic Australian Biron beryl coloured green by vanadium was irradiated with a dose of 10 kGy of 137Cs y rays. The reSUlting ESR spectrum has been modelled as being due to 12 equivalent V02+ centres, each arising from a complex formed from the substitution of V 3 + in the beryl aluminium octahedral site, together with electron loss and motion towards a nearest neighbour oxygen. Each centre can be fitted to an axial spin Hamiltonian H=f3H .g.S+I.A.S,with parameters S = t, I -= ~ and ~I -=1·93±0·01, All ={l70±2)x10-4 em-I,Al. -= (55 ± 2) x 10-4 em-I, and with the z axis at 64° to the crystal c(OOOI) axis and at 74° to a crystal a axis.

Unique Vanadium-Rich Emerald from Malipo, China

“…The super-hyperfine structure of V 2+ and V 4+ in the form of vanadyl ions (VO 2+ ) was previously detected in Australian emerald and Biron gamma-irradiated vanadium-doped synthetic emerald by X-band EPR at room temperature (Hutton et al, 1991). But we were unable to detect any obvious EPR signal of V 2+…”

Electron Spin Resonance of Ti3+ in Synthetic Beryl

“…In a recent report (Hutton et al 1991) we described the ESR detection of vanadium in high quality green synthetic beryl grown by Biron International, Perth, Australia. The present study reports the results on equally high quality pink beryl, which is produced without the normally associated impurity manganese as colouring agent.…”