Characterization of low-temperature-grown epitaxial BaPbO3 and Pb(Zr,Ti)O3/BaPbO3 films on SrTiO3 substrates

The epitaxial BaPbO3 (BPO) and Pb(Zr,Ti)O3 (PZT)/BPO films were grown on (0 0 1)- and (1 1 1)-oriented SrTiO3 (STO) substrates by RF-magnetron sputtering. With the self-template of BPO buffer layer (deposited at 650 °C), BPO main layer and PZT films can be epitaxially grown at temperatures as low as 350 and 475 °C, respectively. The (0 0 1)-oriented BPO film showed a rougher surface and higher work function compared to the (2 2 2)-oriented film. The crystallinity and resistivity of BPO films were independent of their orientation. However, the crystallinity of PZT deposited afterward depends greatly on the orientation of BPO. The crystallinity of PZT deposited on BPO/STO(1 1 1) is significantly higher than that on BPO/STO(0 0 1). The remnant polarization, coercive field, dielectric constant, and resistivity of the PZT/BPO/STO(1 1 1) heterostructure were 35.54 μC/cm2, 102.67 kV/cm, 242, and 1.1-1.6×1011 Ω cm, respectively, which are much better than those of the PZT/BPO/STO(0 0 1) heterostructures.