Regensburg 2004 – scientific programme

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HL: Halbleiterphysik

HL 12: Poster I

HL 12.77: Poster

Monday, March 8, 2004, 16:30–19:00, Poster A

Preparation of Mn-doped ZnO thin films for spintronics — •Erick Guzmán, Holger Hochmuth, Michael Lorenz, Daniel Spemann, Holger von Wenckstern, Rüdiger Schmidt-Grund, Peter Busch, Annette Setzer, Pablo Esquinazi, Heidemarie Schmidt, and Marius Grundmann — Universität Leipzig, Fakultät für Physik und Geowissenschaften

Room temperature ferromagnetism has been theoretically predicted in p-type Mn-doped ZnO [1]. We have grown Mn-doped ZnO thin films on c-plane sapphire substrates by pulsed laser deposition (PLD). The first target was prepared from ZnO and MnO powders above 1000 ^∘C. The structural, electrical, and magnetical thin film properties have been determined by RBS, AFM, ellipsometry, Hall, SQUID, and MFM. The Mn concentration amounts to 4% and is higher than that of the target (nominally 3%). All investigated films are strongly compensated (n ≤ 10¹⁶ cm⁻³) with respect to undoped, naturally n-type ZnO thin films. At 10 K the saturation magnetization of one of those Mn-doped ZnO thin films amounts to 0.018 emu/g, i.e., 0.006 µ _B/Mn-site, whereas at room temperature no significant ferromagnetic contribution was observed. Encouraged by [2], we prepared another target from ZnO and MnO₂ powders, at temperatures below 500 ^∘C. In that way the dependence of the magnetic behaviour in Mn-doped ZnO on charge carrier compensation and Mn clustering can be discussed comparing the two different sample series.

[1] T. Dietl et al.,Science 287 (2000) 1019.

[2] K. V. Rao et al., Nature Materials 2 (2003) 673.