Electrical and pyroelectric properties of in-plane polarized lead lanthanum titanate thin film

Pb0.9La0.1Ti0.975O3 (PLT10) thin films were deposited on SiO2/Si(100) subst rates coated with a ZrO2 buffer layer. Studies by x-ray diffraction and sca nning electron microscopy reveal that the ZrO2 film consists of both tetrag onal and monoclinic phases, with the tetragonal phase being the dominant on e. The PLT10 film has a perovskite structure and the grains in the film hav e a rather uniform size of about 50 nm. By using interdigital transducer (I DT) electrodes the in-plane electrical properties, hysteresis loop, and pyr oelectric coefficient of the PLT10 film were measured. The dielectric const ant and loss factor vary only slightly with frequency in the range 10(3)-10 (6) Hz, with the loss factor being less than 0.01 over the entire range. Th e leakage current density is lower than 2x10(-8) A/cm(2) at a bias field of 5 kV/cm. The remnant polarization and coercive field are 12.6 muC/cm(2) an d 9.93 kV/cm, respectively. The film exhibits a reasonably high pyroelectri c coefficient (95 muC/m(2) K) after it has been poled by applying 120 V ac at 0.1 Hz across the IDT electrodes. (C) 2001 American Institute of Physics .