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Paramagnetism and antiferromagnetic interactions in Cr-doped GaN
L M C Pereira1, T Som, J Demeulemeester
1Instituut voor Kern- en Stralingsfysica and INPAC, K U Leuven, 3001 Leuven, Belgium. IFIMUP and IN-Institute of Nanoscience and Nanotechnology, Faculdade de Ciências da Universidade do Porto, 4169-007 Porto, Portugal. Instituto Tecnológico e Nuclear, UFA, 2686-953 Sacavém, Portugal.
Summary
Chromium-doped Gallium Nitride (GaN) exhibits antiferromagnetic (AFM) interactions between chromium (Cr) atoms. Higher Cr concentrations reduce the effective moment, while annealing affects defect and Cr aggregation.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Gallium Nitride (GaN) is a semiconductor with potential for spintronic applications.
- Doping GaN with magnetic ions like Chromium (Cr) can induce unique magnetic properties.
Purpose of the Study:
- To investigate the magnetic and structural properties of Cr-doped GaN.
- To understand the nature of magnetic interactions and the impact of Cr concentration and annealing.
Main Methods:
- Preparation of Cr-doped GaN thin films via ion implantation.
- Magnetometry measurements for detailed magnetic property analysis.
- Analysis of structural properties and the effects of thermal annealing.
Main Results:
- Demonstrated antiferromagnetic (AFM) interactions between Cr moments in GaN.
- Observed reduction in effective moment per Cr atom with increasing Cr concentration due to AFM coupling.
- Paramagnetic behavior of uncompensated Cr moments.
- Changes in magnetic and structural properties upon thermal annealing attributed to defect annealing and Cr aggregation.
Conclusions:
- Cr-doped GaN exhibits AFM coupling, influencing its magnetic behavior.
- Thermal annealing plays a crucial role in modifying the material's properties by affecting defects and Cr clustering.
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