An EPR study of an S = 3/2 defect in CaWO4

Abstract

AbstractAfter n‐irradiation of CaWO4 up to a dose of 3 × 1019 nvt a spectrum consisting of 12 narrow lines is observed. The angular variation of the spectrum shows that a centre with S = 3/2 located at four magnetically inequivalent sites in the structure is involved. The data are consistent with a spin Hamiltonian ℋ︁ = β S · g · B + S · D. · S, where g and D are noncoincident with principal values gz = 2.048, gy = 2.007, gx = 2.004, D1 = 4.32 × 10−4 cm−1, D2 = 0.31 × 10−4 cm−1 and D3 = −4.63 × 10−4 cm−1. Possible intrinsic lattice defects which might account for this spectrum are discussed.