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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

FE-SEM images of the cross section of Co/InP nanocomposite structure with different deposition times of Co: (a) 0 s, (b) 30 s, (c) 90 s, and (d) 5 min.
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Figure 2: FE-SEM images of the cross section of Co/InP nanocomposite structure with different deposition times of Co: (a) 0 s, (b) 30 s, (c) 90 s, and (d) 5 min.

Mentions: Figure 2a shows the typical FE-SEM image of n-type porous InP template with nearly uniform and square pore arrays. In order to study the growth process of Co in porous InP semiconductor matrix, Co/InP nanocomposites with different deposition times were prepared. The cross-sectional morphologies of different samples are shown in Figure 2b, c, d. There is almost no Co in the inner channel wall of the InP matrix when the deposition time is 30 s, as shown in Figure 2b. When the deposition time increases to 90 s, it was found that a small amount of Co nanoparticles uniformly distribute on the whole inner channel walls of the InP template (Figure 2c). On further increasing the deposition time, the needle-shaped Co forms on the inner pore walls of InP as shown in Figure 2d. It is noted that Co particles prefer to uniformly distribute over the channel wall surface of the InP template than gather at the bottom of channel, which may result from conductivity of n-type porous InP template. In other words, the deposition of metallic Co particles may occur at any position of the pore sidewall surface of InP template (as shown by the schematic of Figure 1), which is different from the "bottom-up" growth mechanism in the insulation templates, such as AAO. Since the channel walls of the insulation templates are stable and nonconductive in the solution, the growth by electrodeposition is always from the bottom to the opening when a conductive layer is fabricated at the bottom side of the insulation channels [9]. Therefore, adjustable electrodepositions may be realized by tuning the conductivity and reactivity of such porous InP matrix, which may open up a new branch in the fabrication of nanocomposite materials. A detailed discussion for this is not given here because it is not the main concern for this article; similar studies in porous silicon matrix have been summarized by Ogata et al. [41].


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)

FE-SEM images of the cross section of Co/InP nanocomposite structure with different deposition times of Co: (a) 0 s, (b) 30 s, (c) 90 s, and (d) 5 min.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 2: FE-SEM images of the cross section of Co/InP nanocomposite structure with different deposition times of Co: (a) 0 s, (b) 30 s, (c) 90 s, and (d) 5 min.
Mentions: Figure 2a shows the typical FE-SEM image of n-type porous InP template with nearly uniform and square pore arrays. In order to study the growth process of Co in porous InP semiconductor matrix, Co/InP nanocomposites with different deposition times were prepared. The cross-sectional morphologies of different samples are shown in Figure 2b, c, d. There is almost no Co in the inner channel wall of the InP matrix when the deposition time is 30 s, as shown in Figure 2b. When the deposition time increases to 90 s, it was found that a small amount of Co nanoparticles uniformly distribute on the whole inner channel walls of the InP template (Figure 2c). On further increasing the deposition time, the needle-shaped Co forms on the inner pore walls of InP as shown in Figure 2d. It is noted that Co particles prefer to uniformly distribute over the channel wall surface of the InP template than gather at the bottom of channel, which may result from conductivity of n-type porous InP template. In other words, the deposition of metallic Co particles may occur at any position of the pore sidewall surface of InP template (as shown by the schematic of Figure 1), which is different from the "bottom-up" growth mechanism in the insulation templates, such as AAO. Since the channel walls of the insulation templates are stable and nonconductive in the solution, the growth by electrodeposition is always from the bottom to the opening when a conductive layer is fabricated at the bottom side of the insulation channels [9]. Therefore, adjustable electrodepositions may be realized by tuning the conductivity and reactivity of such porous InP matrix, which may open up a new branch in the fabrication of nanocomposite materials. A detailed discussion for this is not given here because it is not the main concern for this article; similar studies in porous silicon matrix have been summarized by Ogata et al. [41].

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