Journal of Crystal Growth, Vol.419, 102-107, 2015
Strain effects in epitaxial FeV2O4 thin films fabricated by pulsed laser deposition
The epiLaxial c-axis orientated FeV2O4 films with different thicknesses on SrTiO3. LaAlO3 and MgAl2O4 (001) substrates were fabricated for the first time by pulsed laser deposition, and strain effects On the structure and magnetic anisotropy were investigated. The X-ray diffraction analysis shows that the lattice constants of the FeV2O4 films behave differently on different substrates. The compressive strain in the films on MgAl2O4 is dominantly controlled by the in-plane lattice mismatch. By contrast, the strain states in the films On LaAlO3 and SrTiO3 substrates can be explained by the difference in the thermal expansion coefficients between the films and substrates. In the temperature range investigated from 20 K to 300 K the fully relaxed FeV2O4 thick film is tetragonal with c > a, whereas its bulk is cubic. The magnetic easy axis of all the films is normal to the film plane, independent of substrates, film thickness, and strain states. The out-of-plane magnetic anisotropy is attributed to the high tetragonality with c > a due to the strong spin-lattice coupling. (C) 2015 Elsevier B.V. All rights reserved.