Pulsed Laser Deposition as a Novel Growth Technique of Multiferroic LuFe2O4 Thin Films

Abstract

AbstractGrowth of polycrystalline Lutetium Iron Oxide via pulsed laser deposition in thin film form is reported for the first time herein, and the multiferroic LuFe2O4 phase is stabilized. Fluence and pressure dependent phase growth is demonstrated, along with crystalline structure in vacuum (˜10-5 torr) conditions. Thermodynamic considerations at the laser-target interaction were investigated, as well as at the plume-substrate interface, which reveal that the necessary Gibbs free energy is available in the optimized growth environment to allow formation of the LuFe2O4 polycrystalline phase. The resulting growth rate is found to be related to the Gibbs free energy and concentration of nucleation sites on the substrate. Characterization of the multiferroic aspect of LuFe2O4 entailed direct measurement of the ferroelectricity in the thin film, as well as magnetic behavior, both at various temperatures. In particular, the ferroelectric polarization vs. voltage data yield values of 0.61 μC/cm2 at 300 K to 3.29 μC/cm2 at 183 K; moreover, these data are in agreement with those reported in the literature. Magnetization vs. applied field data shows the magnetization at 300 K to be 180 emu/cm3 and increasing to 200 emu/cm3 at 10 K.