Tunneling Evidence of Half-Metallic Ferromagnetism in La0.7Ca0.3MnO3
نویسندگان
چکیده
Direct experimental evidence of half-metallic density of states (DOS) is observed by scanning tunneling spectroscopy on ferromagnetic La0.7Ca0.3MnO3, which exhibits colossal magnetoresistance (CMR). Tunneling conductance data taken at 77 K, well below the Curie temperature TC ø 260 K, show close resemblance to the spin-split DOS spectrum calculated for the itinerant bands in the ferromagnetic state. The half-metallic spectral characteristics are absent in the paramagnetic state at room temperature, as well as in the undoped antiferromagnetic compound LaMnO3, which shows no CMR. These results directly implicate the half-metallic ferromagnetism in the phenomenon of CMR. [S0031-9007(97)04788-1]
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