Recently, hybrid organic/inorganic interfaces have been used in prototype spin valves, with thin films of La0.7Sr0.3MnO3 as the spin-polarized charge carrier injecting electrode. We have used x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy to study the surface properties of La0.7Sr0.3MnO3 thin films prepared by the channel-spark ablation technique. In particular, preparation of the surfaces by annealing in ultra-high-vacuum surface segregation, the valence electronic structure and work function were studied in order to provide important information for charge injection behavior. It is shown that annealing in vacuum at T<500degreesC removes surface contamination and stabilizes oxygen content. The work-function values change from 4.2 to 4.8 eV depending on surface treatment. A surface layer consisting of SrO and SrCO3 of a few angstrom thick was found, which can significantly influence the spin injection properties at the interfacial region. (C) 2003 American Institute of Physics.
Electronic structure of La0.7Sr0.3MnO3 thin films for hybrid organic/inorganic spintronics applications
Dediu V;Taliani C;
2003
Abstract
Recently, hybrid organic/inorganic interfaces have been used in prototype spin valves, with thin films of La0.7Sr0.3MnO3 as the spin-polarized charge carrier injecting electrode. We have used x-ray photoelectron spectroscopy and ultraviolet photoelectron spectroscopy to study the surface properties of La0.7Sr0.3MnO3 thin films prepared by the channel-spark ablation technique. In particular, preparation of the surfaces by annealing in ultra-high-vacuum surface segregation, the valence electronic structure and work function were studied in order to provide important information for charge injection behavior. It is shown that annealing in vacuum at T<500degreesC removes surface contamination and stabilizes oxygen content. The work-function values change from 4.2 to 4.8 eV depending on surface treatment. A surface layer consisting of SrO and SrCO3 of a few angstrom thick was found, which can significantly influence the spin injection properties at the interfacial region. (C) 2003 American Institute of Physics.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
