Limits...
Magnetic In x Ga 1 - x N nanowires at room temperature using Cu dopant and annealing.

Park YH, Ha R, Park TE, Kim SW, Seo D, Choi HJ - Nanoscale Res Lett (2015)

Bottom Line: The typical diameter of the Cu:In x Ga1 - x N nanowires was 80 to 150 nm, with a typical length of hundreds of micrometers.The as-grown nanowires exhibited diamagnetism.After annealing, the nanowires exhibited ferromagnetism with saturation magnetic moments higher than 0.8 μB (1 μB × 10(-24) Am(2)) per Cu atom at room temperature by the measurements using a superconducting quantum interference device (SQUID) magnetometer.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749, Republic of Korea, younhopark@yonsei.ac.kr.

ABSTRACT
Single-crystal, Cu-doped In x Ga1 - x N nanowires were grown on GaN/Al2O3 substrates via a vapor-liquid-solid (VLS) mechanism using Ni/Au bi-catalysts. The typical diameter of the Cu:In x Ga1 - x N nanowires was 80 to 150 nm, with a typical length of hundreds of micrometers. The as-grown nanowires exhibited diamagnetism. After annealing, the nanowires exhibited ferromagnetism with saturation magnetic moments higher than 0.8 μB (1 μB × 10(-24) Am(2)) per Cu atom at room temperature by the measurements using a superconducting quantum interference device (SQUID) magnetometer. X-ray absorption and X-ray magnetic circular dichroism spectra at Cu L 2,3-edges indicated that the doped Cu had a local magnetic moment and that its electronic configuration was mainly 3d (9). It possessed a small trivalent component, and thus, the n-type behavior of electrical property is measured at room temperature.

No MeSH data available.


Related in: MedlinePlus

Magnetic properties after rapid thermal annealing under a flow of N2. The inset shows the magnetic properties of pure InxGa1 - xN nanowires, indicating diamagnetism.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4493842&req=5

Fig2: Magnetic properties after rapid thermal annealing under a flow of N2. The inset shows the magnetic properties of pure InxGa1 - xN nanowires, indicating diamagnetism.

Mentions: Figure 2 shows the field dependence of magnetization for Cu-doped InxGa1 - xN nanowires, which was measured with a SQUID magnetometer at room temperature and after rapid thermal annealing (800°C). The inset of Figure 2 shows the magnetic properties of the as-grown InxGa1 - xN nanowires, which indicate diamagnetism at room temperature. This is due to the fact that Cu may be interstitially doped into InxGa1 - xN nanowires, since this type of doping is more energetically favorable than substitution doping[13–15]. In order to resolve this issue, the Cu dopants in the InxGa1 - xN nanowires were activated through rapid thermal annealing under a flow of N2 gas. It is known that annealing dissociates Cu by occupying the interstitial sites and substituted Ga or In vacancies in the InGaN lattice. This leads to an increase in the hole concentration, which is essential for the evolution of ferromagnetism in the doped semiconductors[16–18]. As expected, we observed the clear hysteresis loops after rapid thermal annealing (800°C) even at room temperature, which indicates that nanowires possess ferromagnetism with a Curie point exceeding room temperature[18]. The magnetization increases steeply at a low magnetic field and saturates at about >0.15 T. The magnetic moment for Cu-doped InxGa1 - xN nanowires in Figure 2 is shown to be 0.8 μB (1 μB × 10-24 Am2) per Cu atom at room temperature.Figure 2


Magnetic In x Ga 1 - x N nanowires at room temperature using Cu dopant and annealing.

Park YH, Ha R, Park TE, Kim SW, Seo D, Choi HJ - Nanoscale Res Lett (2015)

Magnetic properties after rapid thermal annealing under a flow of N2. The inset shows the magnetic properties of pure InxGa1 - xN nanowires, indicating diamagnetism.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4493842&req=5

Fig2: Magnetic properties after rapid thermal annealing under a flow of N2. The inset shows the magnetic properties of pure InxGa1 - xN nanowires, indicating diamagnetism.
Mentions: Figure 2 shows the field dependence of magnetization for Cu-doped InxGa1 - xN nanowires, which was measured with a SQUID magnetometer at room temperature and after rapid thermal annealing (800°C). The inset of Figure 2 shows the magnetic properties of the as-grown InxGa1 - xN nanowires, which indicate diamagnetism at room temperature. This is due to the fact that Cu may be interstitially doped into InxGa1 - xN nanowires, since this type of doping is more energetically favorable than substitution doping[13–15]. In order to resolve this issue, the Cu dopants in the InxGa1 - xN nanowires were activated through rapid thermal annealing under a flow of N2 gas. It is known that annealing dissociates Cu by occupying the interstitial sites and substituted Ga or In vacancies in the InGaN lattice. This leads to an increase in the hole concentration, which is essential for the evolution of ferromagnetism in the doped semiconductors[16–18]. As expected, we observed the clear hysteresis loops after rapid thermal annealing (800°C) even at room temperature, which indicates that nanowires possess ferromagnetism with a Curie point exceeding room temperature[18]. The magnetization increases steeply at a low magnetic field and saturates at about >0.15 T. The magnetic moment for Cu-doped InxGa1 - xN nanowires in Figure 2 is shown to be 0.8 μB (1 μB × 10-24 Am2) per Cu atom at room temperature.Figure 2

Bottom Line: The typical diameter of the Cu:In x Ga1 - x N nanowires was 80 to 150 nm, with a typical length of hundreds of micrometers.The as-grown nanowires exhibited diamagnetism.After annealing, the nanowires exhibited ferromagnetism with saturation magnetic moments higher than 0.8 μB (1 μB × 10(-24) Am(2)) per Cu atom at room temperature by the measurements using a superconducting quantum interference device (SQUID) magnetometer.

View Article: PubMed Central - PubMed

Affiliation: Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749, Republic of Korea, younhopark@yonsei.ac.kr.

ABSTRACT
Single-crystal, Cu-doped In x Ga1 - x N nanowires were grown on GaN/Al2O3 substrates via a vapor-liquid-solid (VLS) mechanism using Ni/Au bi-catalysts. The typical diameter of the Cu:In x Ga1 - x N nanowires was 80 to 150 nm, with a typical length of hundreds of micrometers. The as-grown nanowires exhibited diamagnetism. After annealing, the nanowires exhibited ferromagnetism with saturation magnetic moments higher than 0.8 μB (1 μB × 10(-24) Am(2)) per Cu atom at room temperature by the measurements using a superconducting quantum interference device (SQUID) magnetometer. X-ray absorption and X-ray magnetic circular dichroism spectra at Cu L 2,3-edges indicated that the doped Cu had a local magnetic moment and that its electronic configuration was mainly 3d (9). It possessed a small trivalent component, and thus, the n-type behavior of electrical property is measured at room temperature.

No MeSH data available.


Related in: MedlinePlus