2005/05/10 by S. R. Shinde, Satishchandra Ogale, S. B. Ogale +28
Chemistry · Materials Science · Physics and Astronomy · #Catalytic Processes in Materials Science #FOS: Physical sciences #Magnetic and transport properties of perovskites and related materials #Materials Science (cond-mat.mtrl-sci) #Pigment Synthesis and Properties #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/0505265
21 pages, 5 figures
arxiv created 2005/05/10 · openalex publication_date 2005/05/10 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We revisit the most widely investigated and controversial oxide diluted magnetic semiconductor (DMS), Co:TiO2, with a new high temperature film growth, and show that the corresponding material is not only an intrinsic DMS ferromagnet, but also supports a percolative mechanism of ferromagnetism. We establish the uniformity of dopant distribution across the film cross section by Z-contrast imaging via scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) at spatial resolution of 0.4 nm and the oxidized 2+ valence state of cobalt by x-ray absorption spectroscopy (XAS). The dependence of magnetic properties on cobalt concentration is consistent with the defect polaron percolation model. The peculiar increase in the transport activation energy above a specific cobalt concentration further emphasizes the polaron contribution to magnetic order.