Abstract
Strain mediated structure, magnetic, and transport properties of spinel ferrites were investigated by growing epitaxial LuxFe3-xO4 (LFO, 0 <= x <= 0: 26) films on SrTiO3 and MgO substrates with inplane compressive and tensile strains, respectively. The lattice parameter of LFO films decreases on SrTiO3 substrates, while increases on MgO substrates with the increasing Lu content. The LFO films on SrTiO3 substrates exhibit larger saturation magnetization and smaller exchange bias and coercive field. Phase shift of anisotropic magnetoresistance is also observed in the LFO films on SrTiO3 substrates. In addition, the nonmagnetic Lu3+ ions in spinel ferrites enhance the spin canting, which further increases the exchange bias and coercive field and strengthens the four-fold symmetry of anisotropic magnetoresistance and the two-fold symmetry of planar Hall effect. (C) 2015 AIP Publishing LLC.