Enhanced pyroelectric and piezoelectric responses in W/Mn-codoped Bi4Ti3O12 Aurivillius ceramics

The pyroelectric and piezoelectric properties of 4 at% Mn-doped Bi4Ti2.9W0.1O12 (BiTW-Mn) Aurivillius ceramic were investigated and compared to Bi4Ti2.9W0.5O12 (BiTW) counterpart, which were fabricated using a conventional solid state reaction method. High resistivities of 4.9 x 10(12) and 2.5 x 10(11) Omega cm at 100 degrees C were obtained in the W-doped and W/Mn-codoped BiT ceramics, respectively. They showed similar activation energies and ionic-p-type mixed conduction mechanisms. Higher pyroelectric coefficients of 57.1 mu C/m(2)K and piezoelectric coefficients of 21 pC/N, as well as much lower dielectric loss of 0.003 were achieved in W/Mn-codoped ceramics. These property changes were mainly induced by Mn-Ti - V-0 defect dipoles. The effect of acceptor doping was evidenced by an internal bias field, shown by a horizontal offset in the polarization-field behavior. The improved properties together with high thermal stability indicate that BiTW-Mn may be a promising candidate for pyroelectric and piezoelectric devices at elevated temperatures.