Regensburg 2016 – wissenschaftliches Programm

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HL: Fachverband Halbleiterphysik

HL 4: Spintronics: Nanostructures and Optics

HL 4.3: Vortrag

Montag, 7. März 2016, 10:00–10:15, H13

Fe doped InAs: what is the exchange interaction? — •Ye Yuan¹, René Hübner¹, Kay Potzger¹, Fang Liu¹, Maciej Sawicki², Tomasz Dietl², Manfred Helm¹, and Shengqiang Zhou¹ — ¹Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany — ²Institute of Physics, Polish Academy of Sciences, Warsaw, Poland

Fe doped InAs layers have been prepared by ion implantation and pulsed laser annealing. Fe ions exist in the +3 valence state when located in Indium sites, which indicates that Fe atoms do not introduce free carriers in the InAs layer and only act as the local spins. However, (In, Fe)As or (In, Fe)As n-type doped with Se exhibits properties typical to a blocked superparamagnet, as proven by both static and dynamic magnetic measurements. This is most probably due to the formation of Fe-rich nanoregions in the InAs matrix, similarly to the case of Cr-doped ZnTe [1]. However, the p-type doping with Zn increases both the saturation magnetization and the Curie temperature. A systematic comparison between (In, Fe)As, (In, Fe)As: Zn and (In, Fe)As: Se leads to the re-affirmation of the pd-exchange as the key gradient in dilute ferromagnetic semiconductors [2].

[1]. K. Kanazawa et al., Nanoscale, 6, 14667-14673 (2014) [2]. T. Dietl et al., Science, 287, 1019-1022 (2000)