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arXiv · 0804.1612

Electrical transport and ferromagnetism in Ga1-xMnxAs synthesized by ion implantation and pulsed-laser melting

M. A. Scarpulla·R. Farshchi·P. R. Stone·R. V. Chopdekar·K. M. Yu·Y. Suzuki·O. D. Dubon
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Abstract

We present a detailed investigation of the magnetic and magnetotransport properties of thin films of ferromagnetic Ga1-xMnxAs synthesized using ion implantation and pulsed-laser melting (II-PLM). The field and temperature-dependent magnetization, magnetic anisotropy, temperature-dependent resistivity, magnetoresistance, and Hall effect of II-PLM Ga1-xMnxAs films have all of the characteristic signatures of the strong p-d interaction of holes and Mn ions observed in the dilute hole-mediated ferromagnetic phase. The ferromagnetic and electrical transport properties of II-PLM films correspond to the peak substitutional Mn concentration meaning that the non-uniform Mn depth distribution is unimportant in determining the film properties. Good quantitative agreement is found with films grown by low temperature molecular beam epitaxy (LT-MBE) and having the similar substitutional Mn_Ga composition. Additionally, we demonstrate that II-PLM Ga1-xMnxAs films are free from interstitial Mn_I because of the high temperature processing. At high Mn implantation doses the kinetics of solute redistribution during solidification alone determine the maximum resulting Mn_Ga concentration. Uniaxial anisotropy between in-plane [-110]and [110] directions is present in II-PLM Ga1-xMnxAs giving evidence for this being an intrinsic property of the carrier-mediated ferromagnetic phase.

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M. A. Scarpulla, R. Farshchi, P. R. Stone, R. V. Chopdekar, K. M. Yu, Y. Suzuki, O. D. Dubon. 2008-04-10. Electrical transport and ferromagnetism in Ga1-xMnxAs synthesized by ion implantation and pulsed-laser melting. https://doi.org/10.1063/1.2890411

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