Title :
Ferromagnetic III-V semiconductor films with high transition temperature
Author :
Däweritz, L. ; Ploog, K.H.
Author_Institution :
Paul-Drude-Inst. fur Festkorperelektronik, Berlin, Germany
Abstract :
The fabrication process of the GaAs-based materials included the deposition of the (Ga,Mn)As alloy at low temperature by conventional solid-source molecular beam epitaxy (MBE) and subsequent thermal annealing. The ferromagnetic and paramagnetic phases are found to coexist in the whole temperature range below Tc. Rapid thermal annealing turns the ferromagnetic (Ga,Mn)As into a paramagnetic matrix. The structural and magnetic properties of granular films prepared by using different annealing recipes have been investigated by X-ray diffraction, superconducting quantum interference device magnetometry, and transmission electron microscopy. The temperature dependence of the lattice parameter a of the nanoclusters also exhibits a significant variation around the bulk MnAs phase transition temperature.
Keywords :
III-V semiconductors; X-ray diffraction; ferromagnetic materials; ferromagnetic-paramagnetic transitions; gallium arsenide; lattice constants; magnetic epitaxial layers; magnetic semiconductors; manganese compounds; molecular beam epitaxial growth; rapid thermal annealing; semiconductor epitaxial layers; transmission electron microscopy; GaAs-based materials; GaMnAs; X-ray diffraction; critical temperature; ferromagnetic phases; ferromagnetic semiconductor thin films; ferromagnetic-paramagnetic phase transition; granular thin films; lattice parameter; magnetic properties; nanoclusters; paramagnetic phases; phase transition temperature; rapid thermal annealing; semiconductor fabrication process; solid-source molecular beam epitaxy; structural properties; superconducting quantum interference device magnetometry; thermal annealing; transmission electron microscopy; Fabrication; III-V semiconductor materials; Molecular beam epitaxial growth; Paramagnetic materials; Rapid thermal annealing; Rapid thermal processing; Semiconductor films; Superconducting films; Superconducting transition temperature; Temperature dependence;
Conference_Titel :
MEMS, NANO and Smart Systems, 2005. Proceedings. 2005 International Conference on
Print_ISBN :
0-7695-2398-6
DOI :
10.1109/ICMENS.2005.51