Orbital polarization and Jahn-Teller distortion of strained La0.5Sr0.5MnO3 thin films

Abstract

We report spectroscopic evidence for orbital-mediated phases in strained La0.5Sr0.5MnO3 thin films by combining soft X-ray spectroscopy and synthesis of manganite thin films. Measurements of polarization-dependent soft X-ray absorption reveal that electronic states responsible for the lowest-energy excitations in C-type antiferromagnetic La0.5Sr0.5MnO3 films have an orbital symmetry of 3z(2) - r(2), while those in A-type AFM. films have an orbital symmetry of x(2)-y(2). Such orbital polarizations in strained films of manganite result from a combined effect of the Jahn-Teller distortion and the electron correlations of Mn 3d electrons. (c) 2006 Published by Elsevier B.V.