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Wet chemical synthesis and magnetic properties of single crystal Co nanochains with surface amorphous passivation Co layers.

Zhou SM, Lou SY, Wang YQ, Chen XL, Liu LS, Yuan HL - Nanoscale Res Lett (2011)

Bottom Line: The as-synthesized Co samples do not include any other adulterants.Room-temperature-enhanced coercivity of NCs was observed, which is considered to have potential applications in spin filtering, high density magnetic recording, and nanosensors.PACS: 61.46.Df; 75.50; 81.07.Vb; 81.07.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Lab for Special Functional Materials of Ministry of Education, Henan University, 475004 Kaifeng, People's Republic of China. smzhou@henu.edu.cn.

ABSTRACT
: In this study, for the first time, high-yield chain-like one-dimensional (1D) Co nanostructures without any impurity have been produced by means of a solution dispersion approach under permanent-magnet. Size, morphology, component, and structure of the as-made samples have been confirmed by several techniques, and nanochains (NCs) with diameter of approximately 60 nm consisting of single-crystalline Co and amorphous Co-capped layer (about 3 nm) have been materialized. The as-synthesized Co samples do not include any other adulterants. The high-quality NC growth mechanism is proposed to be driven by magnetostatic interaction because NC can be reorganized under a weak magnetic field. Room-temperature-enhanced coercivity of NCs was observed, which is considered to have potential applications in spin filtering, high density magnetic recording, and nanosensors. PACS: 61.46.Df; 75.50; 81.07.Vb; 81.07.

No MeSH data available.


(a) Magnetization versus temperature for Co NCs (red) and PSC (black) and (b) RT magnetic hysteresis curves of the Co NCs (red) and PSC (black).
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Figure 4: (a) Magnetization versus temperature for Co NCs (red) and PSC (black) and (b) RT magnetic hysteresis curves of the Co NCs (red) and PSC (black).

Mentions: Despite the presence of the amorphous buffer layer, the NCs display a strong ferromagnetic behavior. Figure 4a shows the magnetization curve as a function of temperature for the NCs and PSC metal. As can be seen, for the NCs, a sharp magnetic transition is observed for T = ~600 K as determined from the inflection point of the magnetization versus temperature curve; the inflection point may result from the enhanced single-crystal Co mass from amorphous Co because the corresponding magnetic transition disappears in PSC under the same conditions. Figure 4b shows the magnetic hysteresis loop, measured at RT with the applied magnetic field perpendicular to the substrate surface. Based on both these curves, coercive fields (Hc) of 355.8 and 93.6 Oe, respectively, for NCs and PSC, saturation magnetizations (Ms) of 125.7 and 162.5 emu/g, respectively, for NCs and PSC, and remnant magnetization (Mr) up to 46.6, and 4.5 emu/g, respectively, for NCs and PSC were determined. A detailed analysis of the magnetic properties as a function of the NC with various amorphous shell sizes will be published separately.


Wet chemical synthesis and magnetic properties of single crystal Co nanochains with surface amorphous passivation Co layers.

Zhou SM, Lou SY, Wang YQ, Chen XL, Liu LS, Yuan HL - Nanoscale Res Lett (2011)

(a) Magnetization versus temperature for Co NCs (red) and PSC (black) and (b) RT magnetic hysteresis curves of the Co NCs (red) and PSC (black).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211350&req=5

Figure 4: (a) Magnetization versus temperature for Co NCs (red) and PSC (black) and (b) RT magnetic hysteresis curves of the Co NCs (red) and PSC (black).
Mentions: Despite the presence of the amorphous buffer layer, the NCs display a strong ferromagnetic behavior. Figure 4a shows the magnetization curve as a function of temperature for the NCs and PSC metal. As can be seen, for the NCs, a sharp magnetic transition is observed for T = ~600 K as determined from the inflection point of the magnetization versus temperature curve; the inflection point may result from the enhanced single-crystal Co mass from amorphous Co because the corresponding magnetic transition disappears in PSC under the same conditions. Figure 4b shows the magnetic hysteresis loop, measured at RT with the applied magnetic field perpendicular to the substrate surface. Based on both these curves, coercive fields (Hc) of 355.8 and 93.6 Oe, respectively, for NCs and PSC, saturation magnetizations (Ms) of 125.7 and 162.5 emu/g, respectively, for NCs and PSC, and remnant magnetization (Mr) up to 46.6, and 4.5 emu/g, respectively, for NCs and PSC were determined. A detailed analysis of the magnetic properties as a function of the NC with various amorphous shell sizes will be published separately.

Bottom Line: The as-synthesized Co samples do not include any other adulterants.Room-temperature-enhanced coercivity of NCs was observed, which is considered to have potential applications in spin filtering, high density magnetic recording, and nanosensors.PACS: 61.46.Df; 75.50; 81.07.Vb; 81.07.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Lab for Special Functional Materials of Ministry of Education, Henan University, 475004 Kaifeng, People's Republic of China. smzhou@henu.edu.cn.

ABSTRACT
: In this study, for the first time, high-yield chain-like one-dimensional (1D) Co nanostructures without any impurity have been produced by means of a solution dispersion approach under permanent-magnet. Size, morphology, component, and structure of the as-made samples have been confirmed by several techniques, and nanochains (NCs) with diameter of approximately 60 nm consisting of single-crystalline Co and amorphous Co-capped layer (about 3 nm) have been materialized. The as-synthesized Co samples do not include any other adulterants. The high-quality NC growth mechanism is proposed to be driven by magnetostatic interaction because NC can be reorganized under a weak magnetic field. Room-temperature-enhanced coercivity of NCs was observed, which is considered to have potential applications in spin filtering, high density magnetic recording, and nanosensors. PACS: 61.46.Df; 75.50; 81.07.Vb; 81.07.

No MeSH data available.