High temperature properties of manganese modified CaBi4Ti4O15 ferroelectric ceramics

The dielectric, piezoelectric and electromechanical properties of manganese modified CaBi4Ti4O15 (CBT) bismuth layer-structured ferroelectric ceramics were determined in the range of room temperature to ∼800 ∘C. The room temperature dielectric permittivity and dielectric loss were found to be 148 and 0.2%, respectively. The piezoelectric coefficients, d33d33 and d15d15, were 14  pC/N and 9  pC/N, with electromechanical coupling factors k33′=8.4% and k15=5.5%k15=5.5%. The mechanical quality factor QQ (sliver extensional mode) was 4300 at room temperature, decreasing with increasing temperature. The remnant polarization and coercive field were found to be 5.2 μC/cm2 and 88 kV/cm, respectively. The excellent piezoelectric, mechanical properties, together with its high Curie temperature (∼800 ∘C) and high electrical resistivity (1×107Ωcm at 500 ∘C), demonstrated the potential of manganese modified CBT ceramics for ultra-high temperature sensing applications.