Observation of room-temperature ferromagnetism in Cu:ZnO films part I; soft X-ray Magnetic Circular Dichroism

ORAL

Abstract

We report direct evidence of room-temperature ferromagnetic ordering in O-deficient Cu:ZnO films by using soft x-ray magnetic circular dichroism and x-ray absorption [1]. Our measurements have revealed unambiguously two distinct features of Cu atoms associated with (i) magnetically ordered Cu ions present only in the oxygen-deficient samples and (ii) magnetically disordered regular Cu$^{2+}$ ions present in all the samples. We find that a sufficient amount of both oxygen vacancies and Cu impurities is essential to the observed ferromagnetism, and a non-negligible portion of Cu impurities is uninvolved in the magnetic order.\\[4pt] [1] T.S. Herng et al, Phys. Rev. Lett. {\bf 105}, 207201 (2010)

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Authors

  • C. Sanchez-Hanke

    • Brookhaven National Laboratory

  • T.S. Herng

    • National University of Singapore

  • D.-C. Qi

    • National University of Singapore

  • T. Berlijn

    • Brookhaven National Laboratory

  • J.B. Yi

    • National University of Singapore

  • K.S. Yang

    • National University of Singapore

  • Y. Dai

    • Shandong University

  • Y.P. Feng

    • National University of Singapore

  • I. Santoso

    • National University of Singapore

  • X.Y. Gao

    • National University of Singapore

  • A.T.S. Wee

    • National University of Singapore

  • W. Ku

    • Brookhaven National Laboratory

  • J. Ding

    • National University of Singapore

  • A. Rusydi

    • National University of Singapore