Synthesis and characterization of Bi-1 (-) xNdxFeO3 thin films deposited using a high throughput physical vapour deposition technique

Abstract

The high throughput synthesis of BiFeO3 and rare earth doped BiFeO3 films using a modified molecular beam epitaxy technique is reported. Optimum conditions for deposition have been established and compositionally graded Bi(1- x)NdxFeO3 (x = 0.08 to 0.24) thin films have been fabricated on platinised silicon substrate (Si/ SiO2/TiO2/Pt) with the aim of finding the optimum Nd dopant concentrations for enhanced piezoelectric properties. For x<0.12, the structure and symmetry were identical to that of the R3c BiFeO3 end member. For x > 0.20, the structure and symmetry were consistent with the NdFeO3 end member (Pnma). For compositions 0.12 < x < 0.2, a gradual transition from R3c to Pnma was observed via a mixed phase region but no compositional interval could be unambiguously identified in which the intermediate PbZrO3-like structure, reported by Karimi et al. (2009) [6], existed as a single phase. Piezoresponse force microscopy remanent hysteresis measurements of the film revealed a statistical increase in the piezoelectric response at x approximate to 0.11 within the R3c region adjacent to the mixed phase field. (c) 2012 Elsevier B.V. All rights reserved.