Direct measurement of the low-temperature spin-state transition in LaCoO3.
LaCoO3 exhibits an anomaly in its magnetic susceptibility around 80 K associated with a thermally excited transition of the Co3+-ion spin. We show that electron energy-loss spectroscopy is sensitive to this Co3+-ion spin-state transition, and that the O K edge prepeak provides a direct measure of the Co3+ spin state in LaCoO3 as a function of temperature. Our experimental results are confirmed by first-principles calculations, and we conclude that the thermally excited spin-state transition occurs from a low to an intermediate spin state, which can be distinguished from the high-spin state.
Department of Physics, University of Illinois at Chicago, Chicago, Illinois 60657, USA.
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RF
Klie
J C
JC
Zheng
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Y
Zhu
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M
Varela
J
J
Wu
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C
Leighton