Ferroelectric and Structural Properties of Sr_(0.5)Ba_(0.5)Nb_2O_6 Thin Films on La_(0.05)Sr_(0.95)TiO_3 Substrate

摘要

C-axis-oriented Sr_(0.5)Ba_(0.5)Nb_2O_6 (SBN) thin films were prepared on a La_(0.05)Sr_(0.95)TiO_3 substrate by pulsed laser deposition. The c-axis orientation and grain size of the SBN thin films depend on the substrate temperature (T_(sub)) and oxygen gas pressure (P_(O_2)) during the deposition. When T_(sub) and P_(O_2) were fixed at 750℃ and 11 mTorr, respectively, a prepared SBN thin film exhibited a distinct c-axis orientation and a smooth surface. The SBN thin film consisted of well-developed grains with a diameter of 150 nm. Its remanent polarization (P_r) and coercive field (E_c) were 2P_r = 23.9 μC/cm~2 and 2E_c = 160 kV/cm, respectively. The band gap of the distinctly c-axis-oriented SBN thin film was about 3.1 eV, which is in agreement with that of the SBN single crystal.