Enhanced dielectric,ferroelectric,and optical properties in rare earth elements doped PMN-PT thin films

摘要

Rare earth(RE=La^(3+),Sm^(3+),Pr^(3+))ion doped Pb(Mgi/3Nb2/3)O3-PbTi03(RE-PMN-PT)ferroelectric thin films with compositions near the morphotropic phase boundary were grown on the Pt/TiO_(2)/S i02/Si(100)substrate using sol-gel/spin coating method.The phase structure,electrical properties,and photoluminescence performance of thin films were investigated systematically.The highly(100)-preferred orientation was obtained in pure perovskite Sm-PMN-0.30PT thin films with an average grain size of 131 nm.After 2.5%Sm^(3+)doping,the PMN-0.30PT thin films exhibited a triple enhancement of dielectric permittivity with a maximum value of 3500 at 1 kHz,a low dielectric loss of 1.3%,and high remanent polarization of 17.5μC/cm^(2)at room temperature.In visible light and near-infrared band,the transmittance rate increased with PT content and showed the highest value of 85%in 2.5%Sm-PMN-0.31PT.In addition,the films presented strong red-orange emission at 599 nm,which was sensitively in temperature range of 248-273 K corresponding to the rhombohedral to monoclinic phase transition temperature.