Berlin 2005 – wissenschaftliches Programm
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O: Oberflächenphysik
O 49: Epitaxie und Wachstum II
O 49.7: Vortrag
Dienstag, 8. März 2005, 17:15–17:30, TU EB407
Fe on GaN: Growth investigations — •Ralph Meijers1, Raffaella Calarco1, Hans Lüth1, Matthias Buchmeier2, and Daniel Bürgler2 — 1Institute of Thin Films and Interfaces (ISG1) and CNI - Centre of Nanoelectronic Systems for Information Technology, Research Center Jülich, 52425 Jülich, Germany — 2Institute of Solid State Research (IFF) and CNI - Center of Nanoelectronic Systems for Information Technology, Research Centre Jülich, 52425 Jülich, Germany
Spintronics is a rapidly evolving research field, which aims to combine ferromagnets with semiconductors to develop devices with new functionality. One of the main goals is achieving an efficient spin-polarized carrier injection into semiconductors at room temperature. One method is to inject carriers from ferromagnetic metals into a semiconductor. The Fe/GaN hybrid system is an interesting layer system, since recent theoretical calculations predict a large spin lifetime in pure GaN. However the lattice mismatch between Fe and GaN is large. The crystalline quality of the heterostructure and the nature of the metal/semiconductor interface are very important.
The epitaxial relation of Fe to GaN was investigated using LEED and XRD together with simulations. The α-Fe(110) plane was found to be parallel to the GaN(0001) plane and formation of three equivalent domains, rotated 1200 against each other, was observed. Using AFM and STM, the surface morphology was investigated and flat domains with sizes up to 500nm were found. SQUID measurements showed ferromagnetic behavior and good homogeneity of the magnetic properties was concluded from ferromagnetic resonance data.