Relaxor behavior of MgO dispersed-Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ (90/10) nanocomposite thin films

摘要

Pb(Mg/sub 1/3/Nb/sub 2/3/)O/sub 3/-PbTiO/sub 3/ [PMN-PT] films were deposited by the radio-frequency (r.f) magnetron sputtering technique and post-annealed. The growth of PMN-PT films as a function of MgO concentration in targets, annealing temperature and heating /cooling rate during annealing was studied. The films deposited from 66 mol% MgO excess target showed good perovskite structure in this study. For film deposited from the target with 66 mol% MgO excess content and postannealed conventionally at 750/spl deg/C for 10 minutes in oxygen flow, preferential [111] orientation of the perovskite phase and pyrochlore phase of less than 3% was observed. And the room temperature dielectric constant was 2500 at 1 kHz. Dielectric and structural properties exhibited relaxor-like behavior. Excess MgO in PMN-PT was homogeneously precipitated and dispersed in grain and grain bounder. The number of MgO nano-particles increased with increasing MgO content in PMN-PT targets.