Influence of oxygen partial pressure on magnetron sputtered Sr0.8Nd0.3Bi2.5Ta2O9+x ferroelectric thin films

During magnetron sputtering deposition of SrBi2Ta2O9 thin films, oxygen gas is introduced in the deposition chamber to compensate the oxygen loss during sputtering. In this paper, the influence of oxygen partial pressure is systematically investigated in sputtering of Sr0.8Nd0.3Bi2.5Ta2O9+x thin films, using X-ray diffraction, X-ray photoelectron spectroscopy and field emission scanning electron microscopy. The studies confirm that at various oxygen partial pressure Nd3+ ions substitute into the bismuth layered perovskite structure, preferentially at the Sr2+ site. The deposition rate, composition, microstructure and polarization properties of the films highly depend on the oxygen partial pressure.