Multiphase Fe-oxide thin films are fabricated on glass substrates by a facing-target sputtering tech- nique. X-ray diffraction and X-ray photoelectron spectroscopy reveal that Fe, Fe3BO4, γ -Fe2BO3B and FeO coexist i...Multiphase Fe-oxide thin films are fabricated on glass substrates by a facing-target sputtering tech- nique. X-ray diffraction and X-ray photoelectron spectroscopy reveal that Fe, Fe3BO4, γ -Fe2BO3B and FeO coexist in the films. High resolution transmission electron microscopy shows the well-defined colum- nar grain structure with the unoxidized Fe as the core and iron-oxide as the shell. The low-field positive and high-field negative magnetoresistances coexist in such a system at room temperature, which can be explained by considering a shell/core model. Nonlinear current-voltage curve and photovoltaic effect further confirm the tunneling-type conduction.展开更多
基金Supported by the National Natural Science Foundation of China (Grant Nos. 50672132 and 60576015) the Key Project of Chinese Ministry of Education (Grant No. 107020)
文摘Multiphase Fe-oxide thin films are fabricated on glass substrates by a facing-target sputtering tech- nique. X-ray diffraction and X-ray photoelectron spectroscopy reveal that Fe, Fe3BO4, γ -Fe2BO3B and FeO coexist in the films. High resolution transmission electron microscopy shows the well-defined colum- nar grain structure with the unoxidized Fe as the core and iron-oxide as the shell. The low-field positive and high-field negative magnetoresistances coexist in such a system at room temperature, which can be explained by considering a shell/core model. Nonlinear current-voltage curve and photovoltaic effect further confirm the tunneling-type conduction.
