Dielectric and Piezoelectric Properties in Mn-Modified (1-x)BiFeO_3-xBaTiO_3 Ceramics

摘要

In the current work, the bulk (1-x)BiFeO_3-xBaTiO_3 system has been studied as a potential lead-free piezoelectric material. Barium titanate (BaTiO_3) in solid solution with bismuth ferrite (BiFeO_3) is observed to stabilize the perovskite structure and improve switching behavior. Samples with various content of BaTiO_3 were prepared via solid-state route, and pure perovskite phase was confirmed by X-ray diffraction. Modification of the BaTiO_3-BiFeO_3 material with Mn improved DC resistivity by one to five orders of magnitude (7.6 ×10~(12) vs. 2.7 ×10~7 Ω·m for 25 mol% BaTiO_3 at room temperature) and polarization hysteresis measurements indicated "hard" ferroelectric behavior with the highest strain response at 33 mol% BaTiO_3. Finally, low-field piezoelectric d_(33) coefficient of 116 pC/N and ferroelectric transition temperature above 450℃ are reported for 25 mol% BaTiO_3 composition.