抄録
Perovskite type lead magnesium niobate Pb(Mg1/3Nb2/3)O3 (PMN) films with BaTiO3 buffer layers on Pt/Ti/SiO2/Si substrates were prepared by Pulsed Laser Deposition. Effect of PMN thickness on the film structural and dielectric properties were investigated mainly by high-resolution X-ray diffraction. The average lattice constant of the whole PMN layer increased with increasing the film thickness. In addition, the surface of PMN has a smaller lattice constant comparing with the inner part of the PMN layer. These two effects can be explained by the thermal expansion coefficient mismatch between the PMN and the bottom layers. The overall dielectric constant of Pt/PMN/BT/Pt/Ti/SiO2/Si exhibits film thickness dependence and has a similar distribution with the average lattice constant. After a simulation with a two-capacitor model, the PMN dielectric constant was distinguished from the overall one. Depending on the thickness, the dielectric property of PMN layer obeys two different mechanisms.
