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Fabrication and magnetic properties of granular Co/porous InP nanocomposite materials.

Zhou T, Cheng D, Zheng M, Ma L, Shen W - Nanoscale Res Lett (2011)

Bottom Line: Co particles had uniform distribution over pore sidewall surface of InP template, which was different from that of ceramic template and may open up new branch of fabrication of nanocomposites.The magnetism of such Co/InP nanocomposites can be gradually tuned from diamagnetism to ferromagnetism by increasing the deposition time of Co.Such Co/InP nanocomposites with adjustable magnetism may have potential applications in future in the field of spin electronics.PACS: 61.46. +w · 72.80.Tm · 81.05.Rm · 75.75. +a · 82.45.Aa.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China. mjzheng@sjtu.edu.cn.

ABSTRACT
A novel Co/InP magnetic semiconductor nanocomposite was fabricated by electrodeposition magnetic Co nanoparticles into n-type porous InP templates in ethanol solution of cobalt chloride. The content or particle size of Co particles embedded in porous InP increased with increasing deposition time. Co particles had uniform distribution over pore sidewall surface of InP template, which was different from that of ceramic template and may open up new branch of fabrication of nanocomposites. The magnetism of such Co/InP nanocomposites can be gradually tuned from diamagnetism to ferromagnetism by increasing the deposition time of Co. Magnetic anisotropy of this Co/InP nanocomposite with magnetization easy axis along the axis of InP square channel was well realized by the competition between shape anisotropy and magnetocrystalline anisotropy. Such Co/InP nanocomposites with adjustable magnetism may have potential applications in future in the field of spin electronics.PACS: 61.46. +w · 72.80.Tm · 81.05.Rm · 75.75. +a · 82.45.Aa.

No MeSH data available.


Related in: MedlinePlus

Magnetic hysteresis loops of the Co/InP nanocomposite structure when the magnetic filed is applied both parallel (circle) and perpendicular (solid line) to the surface of the InP template with deposition time of 5 min. Inset is the magnification curve.
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Figure 5: Magnetic hysteresis loops of the Co/InP nanocomposite structure when the magnetic filed is applied both parallel (circle) and perpendicular (solid line) to the surface of the InP template with deposition time of 5 min. Inset is the magnification curve.

Mentions: Figure 5 shows magnetic hysteresis loops of Co/InP composite structure with the deposition time of 5 min for both perpendicular and parallel orientations, where H// and H⊥ represent the field applied perpendicular and parallel to the surface of the InP template, respectively. Typical coercivities with Hc⊥ = 775 Oe and Hc// = 644 Oe are clearly found in the inset of Figure 5, indicating the enhanced coercivity compared with that of the bulk Co (10 Oe). The relatively larger coercivity in perpendicular orientation suggests weak anisotropy of the system, i.e., magnetization easy axis is perpendicular to the surface of InP template. This magnetic anisotropy of the system is determined by the relatively strong-shape anisotropy of Co nanoparticle arrays embedded in the porous InP matrix compared with the magnetocrystalline anisotropy of hexagonal Co particle. Furthermore, both magnetization curves for perpendicular and parallel are sheared as shown in Figure 5, indicating the existence of inter-particle interactions, which is also manifested by the low squareness ratios, (Mr/Ms)⊥ = 0.34 and (Mr/Ms)// = 0.36. Similar sheared hysteresis loops were also found in Co/ZrO2, Co/AAO, and Ni/AAO nanocomposite materials [2,14,17]. In brief, magnetic anisotropy in the Co/InP nanocomposite structure with easy axis perpendicular to the surface of InP matrix is compatible with that of typical magnetic nanostructures such as nanowires and nanotubes [8,14,16,20,21,29], i.e., the magnetization easy axis is along the long axis of nanostructures, which is the result of the competition between the dominant shape anisotropy and magnetocrystalline anisotropy.


Fabrication and magnetic properties of granular Co/porous InP nanocomposite materials.

Zhou T, Cheng D, Zheng M, Ma L, Shen W - Nanoscale Res Lett (2011)

Magnetic hysteresis loops of the Co/InP nanocomposite structure when the magnetic filed is applied both parallel (circle) and perpendicular (solid line) to the surface of the InP template with deposition time of 5 min. Inset is the magnification curve.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211340&req=5

Figure 5: Magnetic hysteresis loops of the Co/InP nanocomposite structure when the magnetic filed is applied both parallel (circle) and perpendicular (solid line) to the surface of the InP template with deposition time of 5 min. Inset is the magnification curve.
Mentions: Figure 5 shows magnetic hysteresis loops of Co/InP composite structure with the deposition time of 5 min for both perpendicular and parallel orientations, where H// and H⊥ represent the field applied perpendicular and parallel to the surface of the InP template, respectively. Typical coercivities with Hc⊥ = 775 Oe and Hc// = 644 Oe are clearly found in the inset of Figure 5, indicating the enhanced coercivity compared with that of the bulk Co (10 Oe). The relatively larger coercivity in perpendicular orientation suggests weak anisotropy of the system, i.e., magnetization easy axis is perpendicular to the surface of InP template. This magnetic anisotropy of the system is determined by the relatively strong-shape anisotropy of Co nanoparticle arrays embedded in the porous InP matrix compared with the magnetocrystalline anisotropy of hexagonal Co particle. Furthermore, both magnetization curves for perpendicular and parallel are sheared as shown in Figure 5, indicating the existence of inter-particle interactions, which is also manifested by the low squareness ratios, (Mr/Ms)⊥ = 0.34 and (Mr/Ms)// = 0.36. Similar sheared hysteresis loops were also found in Co/ZrO2, Co/AAO, and Ni/AAO nanocomposite materials [2,14,17]. In brief, magnetic anisotropy in the Co/InP nanocomposite structure with easy axis perpendicular to the surface of InP matrix is compatible with that of typical magnetic nanostructures such as nanowires and nanotubes [8,14,16,20,21,29], i.e., the magnetization easy axis is along the long axis of nanostructures, which is the result of the competition between the dominant shape anisotropy and magnetocrystalline anisotropy.

Bottom Line: Co particles had uniform distribution over pore sidewall surface of InP template, which was different from that of ceramic template and may open up new branch of fabrication of nanocomposites.The magnetism of such Co/InP nanocomposites can be gradually tuned from diamagnetism to ferromagnetism by increasing the deposition time of Co.Such Co/InP nanocomposites with adjustable magnetism may have potential applications in future in the field of spin electronics.PACS: 61.46. +w · 72.80.Tm · 81.05.Rm · 75.75. +a · 82.45.Aa.

View Article: PubMed Central - HTML - PubMed

Affiliation: Laboratory of Condensed Matter Spectroscopy and Opto-Electronic Physics, and Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics, Shanghai Jiao Tong University, Shanghai, 200240, People's Republic of China. mjzheng@sjtu.edu.cn.

ABSTRACT
A novel Co/InP magnetic semiconductor nanocomposite was fabricated by electrodeposition magnetic Co nanoparticles into n-type porous InP templates in ethanol solution of cobalt chloride. The content or particle size of Co particles embedded in porous InP increased with increasing deposition time. Co particles had uniform distribution over pore sidewall surface of InP template, which was different from that of ceramic template and may open up new branch of fabrication of nanocomposites. The magnetism of such Co/InP nanocomposites can be gradually tuned from diamagnetism to ferromagnetism by increasing the deposition time of Co. Magnetic anisotropy of this Co/InP nanocomposite with magnetization easy axis along the axis of InP square channel was well realized by the competition between shape anisotropy and magnetocrystalline anisotropy. Such Co/InP nanocomposites with adjustable magnetism may have potential applications in future in the field of spin electronics.PACS: 61.46. +w · 72.80.Tm · 81.05.Rm · 75.75. +a · 82.45.Aa.

No MeSH data available.


Related in: MedlinePlus