We report on tunneling magnetoresistance (TMR) experiments that demonstrate the existence of a significant spin polarization in Co-doped (La,Sr)TiO3-d (Co-LSTO), a ferromagnetic diluted magnetic oxide system (DMOS) with high Curie temperature. These TMR experiments have been performed on magnetic tunnel junctions associating Co-LSTO and Co electrodes. Extensive structural analysis of Co-LSTO combining high-resolution transmission electron microscopy and Auger electron spectroscopy excluded the presence of Co clusters in the Co-LSTO layer and thus, the measured ferromagnetism and high spin polarization are intrinsic properties of this DMOS. Our results argue for the DMOS approach with complex oxide materials in spintronics.
@article{arxiv.cond-mat/0508289,
title = {Co-doped (La,Sr)TiO3-d: a high-Curie temperature diluted magnetic system with large spin-polarization},
author = {G. Herranz and R. Ranchal and M. Bibes and H. Jaffres and E. Jacquet and J. L. Maurice and K. Bouzehouane and F. Wyczisk and E. Tafra and M. Basletic and A. Hamzic and C. Colliex and J. -P. Contour and A. Barthelemy and A. Fert},
journal= {arXiv preprint arXiv:cond-mat/0508289},
year = {2009}
}