Piezoelectricity, pyroelectricity and ferroelectricity in glass ceramics based on PbTiO 3

Abstract

Piezoelectric, pyroelectric and ferroelectric glass ceramics of the PbOTiO 2Al 2O 3SiO 2 system with the addition of other oxides have been studied. A piezoelectric resonance in a freely-suspended sample according to its thickness extension vibration mode is observed. The dielectric, piezoelectric, electromeemical coupling and other parameters, including d 33 = 40 × 10 −12C/N, ϵ 33 T / ϵ 0 = 60, g 33 = 80 × 10 −3 m · V/N, k t = 0.225, are measured. The pyroelectric responses, with the characteristics p = (10−22)× 10 −9 C/cm 2 K, have good linearities from room temperature to nearly 200°C. The existence of ferroelectricity, which gives the most important precondition of the piezoelectricity and pyroelectricity after poling, is verified through: (1) the hysteresis loops by Sowyer-Tower circuit, (2) the ferroelectric domains by TEM, (3) the perovskite-type of ferroelectric crystalline phase PbTiO 3 solid solution by XRD, (4) the abnormality of transition between ferroelectric phase and paraelectric phase, as well as (5) the normalized mode based on an IR absorption band referred to the ferroelectric soft mode of Ti I bond stretching vibration. This material is different either from the corresponding ceramics and single crystals or from non-ferroelectric polar glass ceramics and isotropic gglass ceramics containing ferroelectric crystalline phases. The new characters and features have also been discussed.