Improvement of magnetization and leakage current properties of magnetoelectric BaFeO3 thin films by Zr substitution

Abstract

We report on the synthesis of the magnetoelectric BaFe1−xZrxO3−δ (x=0.5 and 0.7) single-crystalline films whose magnetic and leakage properties have been greatly improved. The films were found to be excellent insulators, up to the leakage current density of about 1.1×10−5A∕cm2 at the bias electric field of 150kV∕cm for the x=0.7 sample. This is much less than 10−2 of that for the BaFeO3−δ single-crystalline film, which means that the leakage current properties have been distinctly improved by zirconium substitution. As for the magnetic properties, the hysteresis loops measured at 5K for the x=0.7 samples apparently show huge saturation magnetization of 0.98μB∕Fe ion, in contrast to 0.09μB∕Fe ion for the x=0.5 sample. This implies that the magnetic ordering for the x=0.7 sample has been greatly enhanced, possibly due to the ferromagnetic spin alignment of Fe ions.