Structural and multiferroic properties of epitaxial γ-Fe2O3-BiFeO3/Bi3.25La0.75Ti3O12 composite bi-layers

Multiferroic properties of gamma-Fe(2)O(3)-BiFeO(3)/Bi(3.25)La(0.75)Ti(3)O(12) epitaxial composite bi-layers grown on SrRuO(3)/SrTiO(3)(1 1 1) are compared with the properties of single phase BiFeO(3) and Bi(3.25)La(0.75)Ti(3)O(12) thin films. The composite bi-layers show well-saturated hysteresis loops with a low coercive field, a high fatigue resistance and high saturation magnetization. The insulating Bi(3.25)La(0.75)Ti(3)O(12) underlayer reduces significantly both the leakage current and the coercive field of the heterostructure (200 kV cm(-1)) at the expense of a lower polarization (20 mu C cm(-2)), while the epitaxial gamma-Fe(2)O(3) secondary phase that develops within the relaxed epitaxial BiFeO(3) matrix allowed for a high saturation magnetization.