Room-Temperature Ferromagnetism in Thin Films of LaMnO₃ Deposited by a Chemical Method Over Large Areas

Hole-doping into the Mott insulator LaMnO₃ results in a very rich magneto-electric phase diagram, including colossal magnetoresistance and different types of charge and orbital ordering. On the other hand, LaMnO₃ presents an important catalytic activity for oxygen reduction, which is fundamental for increasing the efficiency of solid-oxide fuel cells and other energy-conversion devices. In this work, we report the chemical solution (water-based) synthesis of high-quality epitaxial thin films of LaMnO₃, free of defects at square-centimeter scales, and compatible with standard microfabrication techniques. The films show a robust ferromagnetic moment and large magnetoresistance at room temperature. Through a comparison with films grown by pulsed laser deposition, we show that the quasi-equilibrium growth conditions characteristic of this chemical process can be exploited to tune new functionalities of the material