Ferroelectricity and ferromagnetism of La0.5Lu0.5Ni0.5Mn0.5O3 thin films on Nb:SrTiO3 substrates

Epitaxial orthorhombic La0.5Lu0.5Ni0.5Mn0.5O3 (LLNMO) thin films deposited on Nb:SrTiO3 (NSTO) substrates are prepared by pulsed laser deposition and their ferroelectricity and magnetism are investigated using various techniques. It is revealed that the as-prepared thin films are ferromagnetic (FM) insulators. The FM transition occurring at similar to 125 K is evidenced by the well defined hysteresis at low temperature, with a saturated magnetic moment as high as 1.8 mu(B)/f.u. at similar to 5 K. A reversible ferroelectric polarization of similar to 0.2 mu C cm(-2) below similar to 140 K is also observed. The magnetism can be understood by the FM ordering associated with a partially ordered major Ni2+-Mn4+ plus minor Mn3+-Ni3+ configuration, while the ferroelectricity is argued to originate from the A-site disordering of La3+ and Lu3+.