Strain-Induced Change in Local Structure and its Effect on the Ferromagnetic Properties of La0.5Sr0.5CoO3 Thin Films
Joseph C. Woicik, C. K. Xie, J. I. Budnick, W.A. Hines, B.O. Wells
Strained La0.5Sr0.5CoO3 films were epitaxially grown on SrTiO3 and LaAlO3 substrates by pulsed laser deposition. The Co-O bond lengths along in-plane and out-of-plane directions in thin films have been determined by high-resolution extended x-ray absorption fine-structure measurements. The mechanical strain has been shown to largely alter the bond length and induces little change on the bond angle, which is in contrast to many reports of strained manganite films. The change in local structure is responsible for the modification of ferromagnetism in thin films, which is only qualitatively in agreement with double exchange mechanism.