Abstract
We have grown epitaxial Sn substituted cobalt ferrite thin films of various thicknesses on piezoelectric Pb(Mg1/3Nb2/(3))(0.72)Ti0.28O3 substrates and investigated the strain-induced changes of magnetic properties. All films described in this work have been deposited by pulsed laser deposition (PLD) from stoichiometric target of Co0.9Sn0.1Fe2O4. The lattice structure, crystallinity and orientation of the thin films were determined by X-ray diffraction analysis. The magnetization of thin films was measured for both, in-plane and out-of-plane configurations, using a superconductor quantum interference device (SQUID) magnetometer at 300 K. The measurements reveal that the magnetic anisotropy is altered by the strain imposed from the substrate upon application of an electric field. The magnetoelastic coupling is demonstrated by a change of the remanent magnetisation. However, we find that this strain effect is thickness dependent. The biggest strain effect is recorded for the thickest film (400nm) where an electric-field-controlled contraction of the substrate of 0.1% induces a relative change in magnetic moment of 9.3%. The relative change of the remanent magnetisation is reduced with decreasing film thickness and is smaller than 3% for the thinnest film (25nm).