DOI: 10.5176/2301-3516_OPAP14.18
Authors: J. Gao, Z.P. Wu, L. Wan, E.J. Guo
Abstract:
Exitaxial thin films of perovskite manganite doped with tetravalent hafnium, La1-xHfxMnO3 (LHMO), have been fabricated using pulse laser deposition. The electronic structures of these LHMO thin films were investigated using X-ray photoemission spectroscopy (XPS) and Hall effect measurements. XPS spectra of core levels (La 3d, Hf 4f, O 1s, Mn 2p, and Mn 3s) all revealed that these LHMO films are in a mixed valence state of Mn2+ and Mn3+, implying an electron-doped conduction mechanism. Similar to those hole doped manganites, LHMO films also exhibit colossal MR effect. Moreover, a giant electroresistance could be induced by electric currents/fields, demonstrating a remarkable metastability. Strain effect was studied by employing ferroelectric crystal of 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3. The fundamental mechanisms in such tetra-valence Hf doped LaMnO3 are discussed.
Keywords: manganites; perovskite oxides; electron doping; magnetoresistance
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