Room temperature ferromagnetism and spin polarization in Cr doped InN thin films

ORAL

Abstract

Understanding the development of ferromagnetism in transition metal doped semiconductors is a topic of great current interest. We studied the properties of chromium doped InN thin films fabricated by RF sputtering (In$_{1-x}$Cr$_{x}$N, where x= 0, 0.02 and 0.05) on c-sapphire substrates as a possible dilute magnetic semiconductor. We carried out detailed structural, optical, electrical, and magnetic characterization of these samples to investigate the interplay of these different materials properties. These films are found to be polycrystalline without any secondary impurity phases. Optical and electrical measurements indicate that these films are highly degenerate and have a carrier concentration of $\sim $ 10$^{20}$ cm$^{-3}$. Most significantly, we find that these films show room temperature ferromagnetism. We present evidence for intrinsic magnetic properties through measurements of the spin polarization. The results are discussed in the context of carrier mediated ferromagnetism.

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Authors

  • Ambesh Dixit

    Department of physics and astronomy, Wayne State University

  • Sudakar Chandran

    Wayne State University, Wayne State University, Detroit, MI, Department of physics and astronomy, Wayne State University, Department of Physics and Astronomy, Wayne State University, Detroit, MI 48201

  • P. Thapa

    Department of physics and astronomy, Wayne State University

  • R. Panguluri

    Department of Physics and Astronomy, Wayne State University, Detroit MI 48201, USA, Department of physics and astronomy, Wayne State University

  • Vaman Naik

    University of Michigan, Dearborn, University of Michigan-Dearborn, Dearborn, MI 48128, Department of Natural Sciences, University of Michigan-Dearborn, Department of Natural Sciences, University of Michigan-Dearborn, Dearborn, MI

  • Ratna Naik

    Wayne State University, Wayne State University, Detroit, MI, Department of physics and astronomy, Wayne State University

  • J. S. Thakur

    Wayne State University, Department of physics and astronomy, Wayne State University

  • B. Nadgorny

    Department of physics and astronomy, Wayne State University

  • Gavin Lawes

    Wayne State University, Wayne State University, Detroit, MI, Department of physics and astronomy, Wayne State University