Electric properties of Bi₂TeO₅ single crystals

Abstract

Single crystals Bi₂TeO₅ samples have been used for measurements of the dielectric constant, loss and electrical conductivity over a wide range of temperature (20−400°C), frequencies (2.10²−5.10⁷ Hz) and electrical fields (10³−10⁷ V/m). For three crystallographic directions the dielectric constants at room temperature are ε_a = 62, ε_b = 70, ε_c = 36 and gradually increase with increase in temperature. There are relaxation maxima of the tan δ and σ_∼ in temperature dependence. Voltage-current curves obey to the laws of space charge limited currents. The low values of the carrier mobility μ_ef and μ_ef exponentially increase with increase in temperature have been obtained. ac conductivity of the Bi₂TeO₅ single crystals can be described by relation σ_∼ ∼^s. The conductivity stimulation effect have been revealed. The obtained results are treated from position of the hopping conductivity model.