Evidence for O{sub 2p} Hole-Driven Conductivity in La{sub 1{minus}x}Sr{sub x}MnO{sub 3} (0 {le} x {le} 0.7) and La{sub 0.7}Sr{sub 0.3}MnO{sub z} Thin Films
- Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States)
Oxygen K -edge electron-energy-loss spectra have been measured for La{sub 1{minus}x}Sr {sub x}MnO{sub 3} (0{le}x{le}0.7) and La{sub 0.7}Sr {sub 0.3}MnO {sub z} thin films as a function of x and z . The spectra show a prepeak at the Fermi level, corresponding to transitions to empty states in the O{sub 2p} band, at the threshold of the K edge around 529eV. This prepeak systematically increases with an increase in conductivity through divalent doping (x) or oxygen content (z) . This confirms that these materials are charge-transfer-type oxides with carriers having significant oxygen 2p hole character. We argue that, the double exchange mechanism has to include the role of oxygen hole density to satisfactorily describe their transport properties. {copyright} {ital 1997} {ital The American Physical Society}
- Research Organization:
- Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
- DOE Contract Number:
- AC03-76SF00098
- OSTI ID:
- 543868
- Journal Information:
- Physical Review Letters, Vol. 79, Issue 17; Other Information: PBD: Oct 1997
- Country of Publication:
- United States
- Language:
- English
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