Size-effect induced short-range magnetic ordering in germanium nanostructures
Y L Huang1, H L Wang, K C Chan
1Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan.
Journal of Nanoscience and Nanotechnology
|December 7, 2010
Summary
Ordered magnetic states were formed in germanium nanostructures within SiO2. These nanostructures exhibit size-effect induced magnetic ordering at room temperature and below, with unique magnetic behaviors observed at different temperatures.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Nanotechnology
Background:
- Germanium nanostructures embedded in SiO2 are potential candidates for novel magnetic materials.
- Understanding the magnetic properties of such nanostructures is crucial for developing advanced electronic and spintronic devices.
Purpose of the Study:
- To investigate the formation and characteristics of ordered magnetic states in germanium nanostructures within a SiO2 matrix.
- To explore the temperature-dependent magnetic behavior and coupling mechanisms in these nanostructures.
Main Methods:
- Fabrication of germanium nanostructures in SiO2 via sputtering deposition and thermal annealing.
- Characterization using Transmission Electron Microscopy (TEM), Energy Dispersive X-ray Spectrometry (EDS), and Raman Spectroscopy.
- Magnetic property measurements utilizing a Superconducting Quantum Interference Device (SQUID).
Main Results:
- Observed size-effect induced magnetic ordering in germanium nanostructures at room temperature and below.
- Identified superparamagnetic behavior above 230 K.
- Revealed spin reorientation and magnetic coupling below 60 K, indicated by inverted hysteresis loops and negative remanences, suggesting ferri- or antiferromagnetic coupling.
Conclusions:
- Germanium nanostructures in SiO2 exhibit tunable magnetic properties influenced by size and temperature.
- The observed magnetic ordering and coupling mechanisms provide insights into the potential applications of these materials in magnetic storage and spintronics.
