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arXiv · 1003.4195

Asymmetric metal-insulator transition in disordered ferromagnetic films

R. Misra·A. F. Hebard·K. A. Muttalib·P. Wolfle
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Abstract

We present experimental data and a theoretical interpretation on the conductance near the metal-insulator transition in thin ferromagnetic Gd films of thickness b approximately 2-10 nm. A large phase relaxation rate caused by scattering of quasiparticles off spin wave excitations renders the dephasing length L_phi < b in the range of sheet resistances considered, so that the effective dimension is d = 3. The observed approximate fractional temperature power law of the conductivity is ascribed to the scaling regime near the transition. The conductivity data as a function of temperature and disorder strength collapse on to two scaling curves for the metallic and insulating regimes. The best fit is obtained for a dynamical exponent z approximately 2.5 and a correlation length critical exponent ν' approximately 1.4 on the metallic side and a localization length exponent νapproximately 0.8 on the insulating side.

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R. Misra, A. F. Hebard, K. A. Muttalib, P. Wolfle. 2010-03-22. Asymmetric metal-insulator transition in disordered ferromagnetic films. https://doi.org/10.1103/physrevlett.107.037201

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