Relaxor Characteristics of the Phase Transformation in (1 −  x ) BaTiO ₃ – x Bi ( Zn _1/2 Ti _1/2 ) O ₃ Perovskite Ceramics

Abstract

The single‐phase solid solutions of the (1 − x ) BaTiO 3 –( x ) Bi ( Zn 1/2 Ti 1/2 ) O 3 ( BT – BZT ) where x = 0.02–0.15 were prepared to investigate dielectric properties. Crystal structure of samples was obtained by using an X‐ray diffraction technique and Raman spectroscopy. For compositions with x ≤ 0.08, the solid solutions exhibited clear tetragonal symmetry and transitioned to pseudocubic symmetry as the content of BZT increased. The dielectric response exhibited a sharp phase transition within the BT ‐rich region and the composition 0.92 BT –0.08 BZT was characterized by the onset of relaxor characteristics. As the concentration of BZT increased, the phase transition exhibited broader and more diffuse behavior. The polarization as a function of electric field ( P – E ) of these solid solutions also exhibited the same trend. The BT ‐rich compositions showed a normal ferroelectric P – E response with a decrease in loop area as the BZT content increased. The composition at x = 0.08 exhibited a pinched hysteresis loop and with further increase in BZT content, the P – E response was characterized by slim loops.