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Peculiarities of the transport properties of InMnAs layers, produced by the laser deposition, in strong magnetic fields

V. V. Rylkov·A. S. Lagutin·B. A. Aronzon·V. V. Podolskii·V. P. Lesnikov·M. Goiran·J. Galibert·B. Raquet·J. Leotin
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Abstract

Magnetotransport properties of p-InMnAs layers are studied in pulsed magnetic fields up to 30 T. Samples were prepared by the laser deposition and annealed by ruby laser pulses. Well annealed samples show p-type conductivity while they were n-type before the annealing. Surprisingly the anomalous Hall effect resistance in paramagnetic state (T>40 K) and in strong magnetic fields (B > 20 T) appears to be greater than that in ferromagnetic state (T <= 40 K), while the longitudinal resistance rises with the temperature decrease. The negative magnetoresistance saturates in magnetic fields higher then 10T at T near 4 K only, whereas the saturation fields of the anomalous Hall effect resistance are much less (around 2 T at 30K). The total reduction of resistance exceeds 10 times in magnetic fields around of 10T. The obtained results are interpreted on the base of the assumptions of the non-uniform distribution of Mn atoms acting as acceptors, the local ferromagnetic transition and the percolation-like character of the film conductivity, which prevailed under conditions of the strong fluctuations of the exchange interaction. Characteristic scales of the magneto-electric nonuniformity are estimated using analysis of the mesoscopic fluctuations of the non-diagonal components of the magnetoresistivity tensor.

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V. V. Rylkov, A. S. Lagutin, B. A. Aronzon, V. V. Podolskii, V. P. Lesnikov, M. Goiran, J. Galibert, B. Raquet, J. Leotin. 2006-12-27. Peculiarities of the transport properties of InMnAs layers, produced by the laser deposition, in strong magnetic fields. https://arxiv.org/abs/cond-mat/0612641

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