Dependence of Electrical and Thermal Properties on Applied Electric Field in La Doped Barium Titanate Displacive Ferroelectric Perovskites

Abstract

The high dielectric constant and low dielectric loss are the most desirable characteristics of the dielectric materials. Considering the hazardous nature of lead-based ceramics, many research groups have paid great attention to the research on non-lead-based perovskites. The effect of the electric field on the electrical and thermal properties of the Lanthanum doped barium Titanate, one of the main important members of the ferroelectric Perovskites family is studied using the method of double time thermal Green’s function and Kubo formalism. With the help of the Silverman-Joseph Hamiltonian a general expression is derived. The electric field and temperature dependent dielectric constant and specific heat capacity of Ba1-xLaxTiO3 crystal has been investigated. The dielectric constant decreases with increase in temperature and applied electric field component. The variation shows a consequence of the gradual decrease in the Curie temperature of the doped material with the increase in defect concentrations. The results also compared with some previous studies done by the author and other workers on similar other materials.