Influence of compositional variation on structural, electrical and magnetic characteristics of (Ba1-xGd) (Ti1-xFex) O3 (0.2 ≤ x ≤ 0.5)

The effect of composition variation of (Ba1-xGdx)(Ti1-xFex)O-3 (0.2 <= x <= 0.5) on structural, optical, electrical and multiferroic properties was investigated. The polycrystalline samples were fabricated by a chemico-thermal route. While the compound with composition x <= 0.3 has a tetragonal structure akin to BaTiO3, the higher compositions (x > 0.3) crystallize in a mixed phase of the tetragonal and orthorhombic structure. The different polarization mechanisms in the compound were analyzed on the basis of ferroelectric-paraelectric phase transition at 120 degrees C, magnetic reorientation mediated by Gd3+ <-> Fe3+ exchange interaction at 200 degrees C and that induced by antiferromagnetic ordering mediated through the Fe3+ <-> Fe3+ exchange interactions at 380 degrees C. Analysis of ac conductivity on the basis of Jonscher's power law indicates the presence of correlated barrier hopping conduction mechanism in the samples. Among the studied samples, the composition with x = 0.3 exhibiting improved material properties like lower optical band gap and higher optical absorption, high dielectric constant (830 at room temperature and peak value of 3944 at 160 degrees Cand 6478 at 377.5 degrees C), and the room temperature ME coefficient of 1.53 mV cm(-1) Oe(-1) have promising technological applications.