Magnetic ordering in La-substituted BiFeO3-PbTiO3.

Magnetic ordering in La-substituted (Bi1-xLax)0.5Pb0.5Fe0.5Ti0.5O3 is investigated for 0.0 ≤ x ≤ 0.5 samples using magnetization measurement as a function of field and temperature. Occurrence of M-H hysteresis loops in all the samples at low temperature suggests existence of magnetically ordered clusters in an overall paramagnetic host. The magnetic ordering temperature is found to increase with increasing x. A decrease in the c/a ratio with x resulting in a reduction of average Fe3+-O-Fe3+ distance along the c direction is argued to enhanced cooperative magnetic interaction of Fe+3-O-Fe+3. [ABSTRACT FROM AUTHOR]