摘要
We report spectroscopic evidence for orbital-mediated phases in strained La 0.5 Sr 0.5 MnO 3 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 La 0.5 Sr 0.5 MnO 3 films have an orbital symmetry of 3 z 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. © 2006.