Effects of processing temperature on the structure and ferroelectric properties of Ba2−xSrxNaNb5O15 thin films by pulsed laser deposition

Ba2−xSrxNaNb5O15 thin films have been prepared on La0.05Sr0.95TiO3 substrates by pulsed laser deposition. Structural and ferroelectric properties of the thin films were dependent on the substrate temperature (Tsub) and Sr concentration. When the oxygen gas pressure (PO2) and Tsub were fixed at 7.5 mTorr and 700 °C, respectively, the Ba2−xSrxNaNb5O15 (x = 0, 0.6, 1.0 and 1.4) thin films exhibited a highly c-axis orientation. The thin films consisted of well-developed grains and exhibited a smooth surface. The c-axis oriented Ba0.6Sr1.4NaNb5O15 thin film prepared at Tsub = 650 °C also exhibited highly c-axis orientation and good P-E hysteresis loop. The remanent polarization (Pr) and coercive field (Ec) were 2Pr = 24.9 μC/cm2 and 2Ec = 107 kV/cm, respectively.