Crystal Growth and Structural Characteristics of Preferentially a- and b-Axis-Oriented (Bi4-x Nd x )Ti3O12 Films Fabricated by High-Temperature Sputtering

The 3.0-μm (Bi3.25Nd0.75)Ti3O12 (BNT-0.75) films were fabricated on IrO2(101)/ Al2O3(012) substrates by high-temperature sputtering. The XRD pole figure demonstrated that a 3.0-μm BNT-0.75 film deposited on the IrO2 electrode is grown with a strong 10° off-(100)/(010) and a weak (101)/(011) orientations of threefold symmetry. The BNT films represented random orientation near the bottom IrO2 electrode and the intermediate part of the film. In the upper part of the BNT layer, the existence of a- and b-axis-oriented rod-shaped crystals with approximately 0.25 μm width were confirmed. In contrast, the BNT film deposited directly on the Al2O3(012) substrate represented almost completely a- and b-axis orientations in a whole BNT layer.