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Effect of stress on structural transformations in GaMnAs.
J Bak-Misiuk1, P Romanowski, A Misiuk
1Institute of Physics, PAS, al. Lotnikow 32/46, PL-02668 Warsaw, Poland.
Journal of Nanoscience and Nanotechnology
|February 21, 2013
Summary
Annealing granular gallium arsenide (GaAs) films with manganese (Mn) under hydrostatic pressure influences strain and interface roughness. This study reveals how pressure affects the properties of these semiconductor layers.
Area of Science:
- Materials Science
- Semiconductor Physics
- Nanotechnology
Background:
- Gallium arsenide (GaAs) based diluted magnetic semiconductors (DMS) are crucial for spintronic applications.
- Controlling strain and microstructure in Ga(1-x)Mn(x)As/GaAs layers is essential for device performance.
- Annealing is a common post-growth treatment, but its effects under pressure are less understood.
Purpose of the Study:
- To investigate the impact of annealing under ambient and enhanced hydrostatic pressure on the structural properties of Ga(1-x)Mn(x)As/GaAs layers.
- To analyze the changes in strain, Mn concentration, and interface morphology.
- To determine the influence of hydrostatic pressure during annealing.
Main Methods:
- Growth of Ga(1-x)Mn(x)As/GaAs layers using molecular beam epitaxy (MBE) at 230°C.
- Annealing treatment at 500°C under ambient and 1.1 GPa hydrostatic pressure.
- Characterization of strain, Mn concentration, and structural changes using relevant analytical techniques.
Main Results:
- Annealing induced a strain change from compressive to tensile, linked to the formation of zinc blende MnAs inclusions.
- Manganese (Mn) concentration remained constant before and after annealing, irrespective of pressure.
- Hydrostatic pressure during annealing significantly affected the strain state and interface roughness of the layers.
Conclusions:
- Annealing granular GaAs:(Mn, Ga)As films under hydrostatic pressure offers a method to tune strain and interface properties.
- The formation of MnAs inclusions is a key factor in strain modification.
- Hydrostatic pressure is a critical parameter influencing the microstructure and strain evolution in these DMS materials.
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