Structural, Magnetic, and Transport Properties of Fe(1-x)Rh(x)/MgO(001) Films Grown by Molecular-Beam Epitaxy

ORAL

Abstract

Fe(1-x)Rh(x) layers are grown with varying rhodium fraction x on (001)-oriented MgO substrates by molecular-beam epitaxy. Film structural, morphological, magnetic, and transport properties are investigated. At room temperature, layers are ferromagnetic (FM) for x ≤ 0.48 and antiferromagnetic (AF) for x > 0.48. Separating the two magnetically ordered phases at x = 0.48 is an abrupt change in the Fe(1-x)Rh(x) lattice parameter of Δa = 0.0028 nm (Δa/a = −0.9%). For AF layers, the FM state is recovered by heating across a first-order phase transition. The transition leads to a large resistivity modulation, Δρ/ρ = 80%, over a narrow temperature range, ΔT = 3 K, in stoichiometric Fe(0.50)Rh(0.50)/MgO(001). The resistivity change is explained using a model based on independent spin conduction channels. For samples with compositions deviating from x = 0.50, fluctuations broaden ΔT and defect scattering reduces Δρ/ρ.

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Presenters

  • Antonio Mei

    Materials Science & Engineering, Cornell University

Authors

  • Antonio Mei

    Materials Science & Engineering, Cornell University

  • Darrell G. Schlom

    Cornell University, Cornell University, Ithaca, New York 14853, USA, Department of Materials Science and Engineering, Cornell University, Department of Materials Science and Engineering, Kavli Institute at Cornell for Nanoscale Science, Cornell University, Materials Science & Engineering, Cornell University, Department of Materials Science and Engineering,, Cornell University, Materials Science and Engineering, University of Cornell