Magnetoelectric investigations in La-modified bismuth layered ferroelectromagnetics

Five-layered Aurivillius compounds of SrBi5−xLaxFeTi4O18 (SBLFT) with x = 0.0, 0.65, 0.75 and 0.85 are synthesized to study ferroelectromagnetic physical properties and the effect of La substitution on the magnetoelectric coefficient. It is seen that the room temperature crystal structure of the samples is pseudo-orthorhombic and the unit cell volume expands with the increase of La content. A maximum remanent polarization (Pr) of 6.1 μC cm−2 is obtained for x = 0.65 and the value decreases with further increase of La. Piezoelectric charge coefficient (d33) of 27 pC N−1 is obtained for the samples. Magnetic hysteresis and temperature dependent magnetization suggest the presence of antiferromagnetism with canted spins. Magnetoelectric coefficient (α) = 6.3 mV cm-Oe−1 is achieved for the sample with La content of 0.65.