Nd-substituted SrBi2Ta2O9 ferroelectric thin films prepared by radio frequency magnetron sputtering

Nd-substituted SrBi2Ta2O9 (SNBT) thin films are sputtered on Pt/Ta/SiO2/Si substrates. X-ray diffraction and x-ray photoelectron spectroscopy studies indicate that Nd3+ is substituted into the bismuth layered perovskite structure, preferentially at the Sr2+ site. The annealed thin film is polycrystalline with plate/needle-like grain microstructure. Secondary ion mass spectrometry results show that elements in SNBT thin film homogeneously distribute along film depth and interfacial diffusion takes place during post annealing. The Nd substitution leads to enhanced remnant polarization (2Pr = 18 μC/cm2) and reduced coercivity (2Ec = 64 kV/cm) at 180 kV/cm measured at 25 °C. After 1010 switching cycles, around 9% remnant polarization is decreased.