Dielectric and Piezoelectric Properties in Mn-Modified (1-x)BiFeO3-xBaTiO3 Ceramics

In the current work, the bulk (1-x)BiFeO3-xBaTiO(3) system has been studied as a potential lead-free piezoelectric material. Barium titanate (BaTiO3) in solid solution with bismuth ferrite (BiFeO3) is observed to stabilize the perovskite structure and improve switching behavior. Samples with various content of BaTiO3 were prepared via solid-state route, and pure perovskite phase was confirmed by X-ray diffraction. Modification of the BaTiO3-BiFeO3 material with Mn improved DC resistivity by one to five orders of magnitude (7.6 x 1012 vs. 2.7 x 107 center dot m for 25 mol% BaTiO3 at room temperature) and polarization hysteresis measurements indicated "hard" ferroelectric behavior with the highest strain response at 33 mol% BaTiO3. Finally, low-field piezoelectric d(33) coefficient of 116 pC/N and ferroelectric transition temperature above 450 degrees C are reported for 25 mol% BaTiO3 composition.