Effect of Sr-doping on multiferroic properties of Bi0.8La0.2Fe0.9Mn0.1O3

The effect of Sr-doping on ferroelectricity and ferromagnetism at room temperature has been studied for Bi0.8La0.2Fe0.9Mn0.1O3 ceramic system. X-ray diffraction shows that a structural phase transition occurs from rhombohedral structure of BiFeO3 (space group R3c) to orthorhombic structure of Bi0.8La0.2FeO3 (space group C222  ). Substitutions of Sr-ions in Bi-site and Mn-ions in Fe-site do not induce any further structural change. Moreover, doping of Sr-ions plays a crucial role to obtain single phased samples. DTA and TGA studies show that both the magnetic transition temperature (TMTM) and the ferroelectric transition temperature (TCTC) decrease for Bi0.7Sr0.1La0.2Fe0.9Mn0.1O3. Sr-doping enhances the ferroelectric property by increasing the electric polarization. M–HM–H measurement shows that Sr-ions partially destroy the spin cycloidal structure in it giving rise to weak ferromagnetism (nonlinearity) at room temperature.

► Enhanced ferroelectricity and ferromagnetism at room temperature has been observed, due to Sr-doping.
► Impurity phase can be eliminated and a single phased sample can be achieved by Sr-doping.
► The magnetic and the ferroelectric transition temperature decreases due to this doping.