Unconventional magnetic transition and transport behavior in Na0.75CoO2

By T. Motohashi, R. Ueda, E. Naujalis, T. Tojo, I. Terasaki, T. Atake, M. Karppinen, H. Yamauchi. 2002

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Here we report an unconventional magnetic and transport phenomenon in a layered cobalt oxide Na x CoO 2 . Only for x=0.75, a magnetic transition of the second order was clearly detected at T m ∼22 K where an apparent specific-heat jump, an onset of extremely small spontaneous magnetization, and a kink in resistivity came in. Moreover large positive magnetoresistance effect was observed below T m . These features of the transition strongly indicate the appearance of an unusual electronic state that may be attributed to the strongly correlated electrons in Na 0 . 7 5 CoO 2 .

Subfields: Condensed Matter Physics, Electronic, Optical and Magnetic Materials, Materials Chemistry

View Paper: https://www.semanticscholar.org/paper/fc84f650b1a515261e59c046eadcea38fdd69cb9