Structural and magnetic properties of pulsed laser annealed GaMnAs


Structural and magnetic properties of pulsed laser annealed GaMnAs

Bürger, D.; Pandey, M.; Zhou, S.; Grenzer, J.; Reuther, H.; Anwand, W.; Helm, M.; Schmidt, H.

Magnetic semiconductors with high Curie temperatures and large coercivity are very promising materials for spintronic applications. An approach to fabricate GaMnAs is the Mn-implantation of GaAs followed by pulsed laser annealing (PLA). We investigated the influence of Mn concentration and PLA conditions, e.g. number of pulses, pulse length, and pulse energy, on the structural and magnetic properties of GaMnAs. Using SQUID magnetometry, we revealed a strong decrease of the saturation magnetization with increasing number of pulses. HRXRD-measurements revealed a lattice expansion normal to the surface after implantation. PLA leads either to a strain decrease (1 pulse) or even to a strain over compensation (10 pulses). We conclude that Mn implantation into GaAs followed by PLA is not sufficient for increasing the Curie temperature in GaMnAs. In addition, the drawback of the Mn implantation is the loss of As from the GaAs surface as detected by means of Auger electron spectroscopy. Heat transfer calculations and coimplantation with suitable elements are possible approaches to enhance the properties of GaMnAs.

Keywords: pulsed laser annealing; DMS; GaMnAs; implantation; ferromagnetism

  • Lecture (Conference)
    DPG Frühjahrstagung der Sektion Kondensierte Materie (SKM), 22.-27.03.2009, Dresden, Deutschland

Permalink: https://www.hzdr.de/publications/Publ-12593
Publ.-Id: 12593