Synthesis, Structural and Magnetic Properties of Cobalt-Doped GaN Nanowires on Si by Atmospheric Pressure Chemical Vapor Deposition.
Zhe Chuan FengYu-Lun LiuJeffrey YiinLi-Chyong ChenKuei-Hsien ChenBenjamin KleinIan T FergusonPublished in: Materials (Basel, Switzerland) (2022)
GaN nanowires (NWs) grown on silicon via atmospheric pressure chemical vapor deposition were doped with Cobalt (Co) by ion implantation, with a high dose concentration of 4 × 10 16 cm -2 , corresponding to an average atomic percentage of ~3.85%, and annealed after the implantation. Co-doped GaN showed optimum structural properties when annealed at 700 °C for 6 min in NH 3 ambience. From scanning electron microscopy, X-ray diffraction, high resolution transmission electron microscope, and energy dispersive X-ray spectroscopy measurements and analyses, the single crystalline nature of Co-GaN NWs was identified. Slight expansion in the lattice constant of Co-GaN NWs due to the implantation-induced stress effect was observed, which was recovered by thermal annealing. Co-GaN NWs exhibited ferromagnetism as per the superconducting quantum interference device (SQUID) measurement. Hysteretic curves with Hc (coercivity) of 502.5 Oe at 5 K and 201.3 Oe at 300 K were obtained. Applied with a magnetic field of 100 Oe, the transition point between paramagnetic property and ferromagnetic property was determined at 332 K. Interesting structural and conducive magnetic properties show the potential of Co-doped GaN nanowires for the next optoelectronic, electronic, spintronic, sensing, optical, and related applications.
Keyphrases
- room temperature
- electron microscopy
- high resolution
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- quantum dots
- ionic liquid
- metal organic framework
- reduced graphene oxide
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- low dose
- molecularly imprinted
- magnetic resonance imaging
- mass spectrometry
- high glucose
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- stress induced
- gas chromatography mass spectrometry
- tandem mass spectrometry
- climate change
- crystal structure