Effect of oxygen content during sputtering on the electrical properties of bismuth ferrite thin films

Abstract

The effect of oxygen content during sputtering on the leakage mechanism and the ferroelectric properties of BiFeO3 with a sintering aid of CuO (CuO-BFO) was investigated, where all thin films with (100) orientation were grown on SrRuO3/LaAlO3(100) substrates by radio frequency sputtering with an oxygen content of 0-40%. The ferroelectric properties in CuO-BFO are tailored by changing the oxygen content during sputtering, indicating a small growth window. The Schottky emission dominates the leakage behavior regardless of oxygen content. The thin film with an oxygen content of ∼20% during sputtering has a higher remanent polarization of 2Pr ∼ 184.7 μC/cm2, due to its lower leakage current density and an improved phase purity. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) In this Letter, BiFeO3 thin films with a sintering aid of CuO (CuO-BFO) were investigated. Schottky emission is involved in their leakage mechanism regardless of the oxygen content during sputtering. In contrast, the remanent polarization of CuO-BFO thin films is strongly dependent on the oxygen content during sputtering, where a higher remanent polarization of 2Pr ∼ 184.7 μC/cm2 is induced for the thin film with an oxygen content of ∼20% during sputtering. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.