Dielectric losses in Ba_xSr_(1-x)TiO_3 as a function of temperature in para-electric phase

摘要

Using method of double time Green's function, a general expression is obtained for dielectric losses in Ba_xSr_(1-x)TiO_3 ferro-electric crystals. Then, by using the result (T-T'_c) tan δ = α + βT+γT~2. temperature dependence of dielectric losses of various crystals are calculated and the results are found in good agreement with the results of others. In para-electric phase, the dielectric loss decreases with increasing temperature showing the Curie-Weiss behaviour of the dielectric loss.