Studies on compensating valency substituted BaTi_(1−x)Mn _x/2Nb _x/2O₃ ceramics

Abstract

The paper reports investigations of relative permittivity, ε_r, electrical conductivity, σ, saturation polarization, P_s, infrared absorption and structural properties of compensating valency substituted BaTiO₃. The compositions investigated are BaTi_(1−x)Mn_x/2Nb_x/2O₃ forx = 0.00; 0.025; 0.05; 0.1; 0.2; 0.4. The compositions forx < 0.1 are observed to be ferroelectric and the transition temperature and value of ε_r are observed to decrease as concentration of substitution is increased. The dielectric investigations are carried out on two sets of samples (i) as sintered and (ii) annealed. Annealing is observed to improve quality factor‘Q’ of the materials with a consequent reduction in the ε_r. The observations on ε_r and saturation polarization suggest that additional material engineering efforts are required to improve the material properties.