Electron paramagnetic resonance of Cu 2+ in CaWO 4

Abstract

The electron paramagnetic resonance spectrum has been observed for the CU 2+ ion in a distorted tetrahedral environment in CaWO 4. The spectrum has been fitted to an axial spin Hamiltonian, leading to g-values | g ‖| = 2.072 ± 0.005 and | g ⊥| = 2.286 ± 0.005 and hyperfine splitting constants | A ‖ | = 38.5 × 10 −4 cm −1, |A ⊥ 55.6 x 10 −4 cm −1 for the 65Cu isotope and | A ‖ | = 41.1 × 10 −4 cm −17, | A ⊥ | = 59.5 × 10 −4 cm −1 for the 65 Cu isotope. The results are discussed in terms of the observations of Cu 2+ paramagnetic spectra in other tetrahedral crystal fields, and an interpretation of the present results in terms of 4 p admixture into the 3 d electronic wave function of the paramagnetic ion is suggested.