Dielectric and ac conductivity studies in as‐grown Ga₂Te₃ crystals with the defect zinc‐blende structure

Abstract Ga₂Te₃ crystallizes in the zinc‐blende structure where one‐third of the cation sites are vacant. The dielectric properties of as‐grown Ga₂Te₃ crystals have been studied in the frequency range from 10² to 10⁹ Hz. Below room temperature, the dielectric constant is around 20 and almost independent of temperature. The ac conductivity is found to obey a power law σ_ac ∼ ω^s, with s ∼ 1 indicating that the conduction is due to hopping of localized charge carriers. Above room temperature the dielectric constant shows an S‐shaped step‐like increase up to a very large value around 10⁴. The relaxation is found to be of thermal activated Debye type, the relaxation time changes as $\tau = \tau _0 \,{\rm exp}(E_\tau /kT)$ ($E_\tau \approx 0.27\,{\rm eV}$). The activation energy of the relaxation nearly coincides with that deduced from conductivity. These results are analyzed using the Maxwell Wagner model and the space charge model.