Photo-EPR studies of KTN-1.2: Evidences of the Nb 4+-O - polaronic excitons

Abstract

Strongly anisotropic photoinduced electron paramagnetic resonance spectrum was found in the KTa 1-xNb xO 3 crystals with x = 0.012 at T < 10 K, which is described well within the model of the center with S = 1, g ∥ = 0.82 ±0.04, g ⊥ = 0.52 ±0.04, and D = 0.44 ±0.03 cm -1. Analysis shows that this spectrum originates from the Nb 4+-O - polaronic exciton in the triplet state.