Magnetization and magnetoelectric effect in Bi1-xLaxFeO3 (0≤x≤0.15)

We report on magnetization and magnetocapacitance measurements in the Bi1-xLaxFeO3 series for 0 <= x <= 0.15. We confirm that doping with La reduces the threshold magnetic field H-c for cancelling the magnetic spiral phase, and we show that H-c decreases as the La content increases up to x=0.15, which is the highest concentration for maintaining the noncentrosymmetric rhombohedral structure of BiFeO3. Measurements of the dielectric constant as a function of magnetic field in the series also show a maximum magnetocapacitance for x=0.15.