An electron paramagnetic resonance and magneto-optical study of vanadium in

Abstract

The vanadium-related defects in high-resistivity Bridgman-grown Zn x Cd 1−x Te (x = 0.04, 0.10) crystals have been studied by electron paramagnetic resonance (EPR) and magnetic circular dichroism absorption spectroscopy (MCDA). Only one vanadium-related spectrum is observed by EPR, which is attributed to a V 2+ defect in orthorhombic point symmetry. Its spin Hamiltonian parameters are electron spin S = 3/2, Land é g-tensor g xx = 1.976, g yy = 1.959, g zz = 1.974, crystal field splitting parameters D = −0.933 cm −1 and E = −0.073 cm −1 , nuclear spin I = 7/2, hyperfine tensor A xx = −65 × 10 −4 cm −1 , A yy = −57 × 10 −4 cm −1 , A zz = −65 × 10 −4 cm −1 with the principal axes x , y, z oriented along the [110] , [001], [−110] directions respectively. The MCDA measurements performed on the same crystals show in addition to the absorption bands of the V 2+ ion those of the V 3+ ion, a defect not observed by EPR; the non-observation of the V 3+ EPR spectrum is ascribed to a strong zero-field splitting of the 3 A 2 groundstate. The low point symmetry of the V 2+ defect is attributed to the formation of V Cd -X Cd second nearest neighbour complexes in the Zn-alloyed CdTe samples.

Role of zinc in the optical properties of vanadium-doped CdZnTe

“…In a recent paper, von Bardeleben et al [23] invoke, from a combined EPR and MCDA results, the formation of V Cd -X Cd second nearest neighbour complexes in the Zn-alloyed CdTe samples. Thus, we can conclude that the 1 eV emission band and the V Cd -X Cd complex centre are anticorrelated.…”

Investigation of nonequilibrium carrier transport in vanadium-doped CdTe and CdZnTe crystals using the time-resolved four-wave mixing technique

“…Cd vacancies. It has also been proposed that [V 2+ ] may create a complex with Zn which introduces deep acceptor level [18,19].…”

High-frequency and -field electron paramagnetic resonance of vanadium(IV, III, and II) complexes

“…cm -1 , E = 0.073(4) cm -1 , g x = 1.976, g y = 1.959, g z = 1.974 [135]. The only relevant molecular complex that was studied early on was vanadocene (VCp 2 , bis( 5cyclopentadienyl)vanadium(II)), doped into a single crystal of ferrocene and investigated by conventional (22.5 GHz) EPR [136].…”