Physical properties of FeGa2Se4 under an applied alternating current

The temperature and frequency dependences of the permittivity and conductivity of FeGa 2 Se 4 crystals under an applied alternating current are investigated. The values of the permittivity are determined. It is assumed that an increase in ɛ′ is related to an increase in the defect concentration with temperature. It is established that the regularity σ ∝ f S (0.1 ≤ S ≤ 1.0) is fulfilled for conductivity in the temperature range of 294–374 K at frequencies of 10 4 -2 × 10 5 Hz. In the FeGa 2 Se 4 crystal, the variation in the frequency dependence of the conductivity can be explained as follows: there are the clusters in crystals containing localized states with almost identical energy, and the electron hopping occurs between them. In the FeGa 2 Se 4 compound, the conductivity is characterized by band-hopping mechanisms.