Dielectric properties of pulsed laser deposited films of PbMg1/3Nb2/3-PbTiO3 and PbSc1/2Nb1/2O3-PbTiO3 relaxor ferroelectrics

Highly oriented perovskite films of PbMg1/3Nb2/3-PbTiO3 and PbSc1/2Nb1/2O3- PbTiO3 with compositions near the morphotropic phase boundary were formed b y pulsed laser deposition on La0.5Sr0.5CoO3/MgO (100). The dielectric prope rties of the films were studied over the frequency range of 100 Hz-1 MHz in the temperature range 20-350 degrees C. The room temperature polarization and dielectric permittivity of 250-nm-thick films were close to those in bu lk ceramics. The films exhibited relaxor-type behavior with thermal hystere sis and with the temperatures of the dielectric peaks corresponding to thos e in the bulk. The width of the transition in the films was larger than in bulk ceramics. The properties of the films were found to be influenced by t he small grain size rather than by the interfaces of the films. (C) 1999 Am erican Institute of Physics. [S0021- 8979(99)01921-0].