Stress-induced magnetization for epitaxial spinel ferrite films through interface engineering

This study found stress-induced magnetization for epitaxial ferrite films with spinel structure. We grew (111)- and (001)-epitaxial Ni0.17Zn0.23Fe2.60O4(NZF) films on CeO2/Y0.15Zr0.85O1.93(YSZ)/Si(001) and oxide single-crystal substrates, respectively. There is a window of lattice mismatch (between 0 and 6.5%) to achieve bulk saturation magnetization (Ms). An NZF film grown on CeO2/YSZ//Si(001) showed tensile stress, but that stress was relaxed by introducing a ZnCo2O4(ZC) buffer layer. NZF films grown on SrTiO3(ST)(001) and (La,Sr)(Al,Ta)O-3(LSAT)(001) had compressive stress, which was enhanced by introducing a ZC buffer layer. In both cases, bulk Ms was achieved by introducing the ZC buffer layer. This similarity suggests that magnetization can be controlled by the stress. (C) 2004 American Institute of Physics.