Limits...
Strong textured SmCo5 nanoflakes with ultrahigh coercivity prepared by multistep (three steps) surfactant-assisted ball milling.

Zuo WL, Zhao X, Xiong JF, Zhang M, Zhao TY, Hu FX, Sun JR, Shen BG - Sci Rep (2015)

Bottom Line: The high coercivity of 26.2 kOe for SmCo5 nanoflakes are obtained by multistep (three steps) surfactant-assisted ball milling.The magnetic properties, phase structure and morphology are studied by VSM, XRD and SEM, respectively.The results demonstrate that the three step ball-milling can keep more complete crystallinity (relatively less defects) during the process of milling compared with one step high energy ball-milling, which enhances the texture degree and coercivity.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.

ABSTRACT
The high coercivity of 26.2 kOe for SmCo5 nanoflakes are obtained by multistep (three steps) surfactant-assisted ball milling. The magnetic properties, phase structure and morphology are studied by VSM, XRD and SEM, respectively. The results demonstrate that the three step ball-milling can keep more complete crystallinity (relatively less defects) during the process of milling compared with one step high energy ball-milling, which enhances the texture degree and coercivity. In addition, the mechanism of coercivity are also studied by the temperature dependence of demagnetization curves for aligned SmCo5 nanoflakes/resin composite, the result indicates that the magnetization reversal could be controlled by co-existed mechanisms of pinning and nucleation.

No MeSH data available.


Related in: MedlinePlus

The SEM images of SmCo5 powder with different BM time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4536656&req=5

f3: The SEM images of SmCo5 powder with different BM time.

Mentions: Figure 3 shows the morphology evolution of nanoflakes with the BM time from 0 to 24 h. It is obviously that the start powder is irregular shape and the size are around 50–400 μm. After 4 h low energy BM (150 rpm), the start powders are crushed down to smaller particles and with the average diameter of 5 μm, which more intuitively demonstrates that the low energy is effective in the grain refinement. However, the morphology of sheet type can hardly be seen. With the increase of milling time and milling energy reach to 12 h and 200 rpm, respectively. The particles become smaller and more uniformly. Some sheet-type morphology, with micron or submicron thickness and 1–5 μm length, can be seen obviously. With further increasing milling time and energy, the SmCo5 nanoflakes, with thickness about 50–200 nm and length in the range of 1–2 μm, are prepared. Furthermore, the nanoflakes form “kebab-like” morphology due to the c-axis texture and magnetostatic interaction, which indicates that the easy magnetization direction of as-milled SmCo5 nanoflakes is perpendicular to the surface of the flakes. It is interesting that the nanoflakes with multistep BM shows smaller length and aspect ratio compared with those of usual one step high energy BM6789101112, which is favorable for decreasing the demagnetization fields of SmCo5 nanoflakes.


Strong textured SmCo5 nanoflakes with ultrahigh coercivity prepared by multistep (three steps) surfactant-assisted ball milling.

Zuo WL, Zhao X, Xiong JF, Zhang M, Zhao TY, Hu FX, Sun JR, Shen BG - Sci Rep (2015)

The SEM images of SmCo5 powder with different BM time.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4536656&req=5

f3: The SEM images of SmCo5 powder with different BM time.
Mentions: Figure 3 shows the morphology evolution of nanoflakes with the BM time from 0 to 24 h. It is obviously that the start powder is irregular shape and the size are around 50–400 μm. After 4 h low energy BM (150 rpm), the start powders are crushed down to smaller particles and with the average diameter of 5 μm, which more intuitively demonstrates that the low energy is effective in the grain refinement. However, the morphology of sheet type can hardly be seen. With the increase of milling time and milling energy reach to 12 h and 200 rpm, respectively. The particles become smaller and more uniformly. Some sheet-type morphology, with micron or submicron thickness and 1–5 μm length, can be seen obviously. With further increasing milling time and energy, the SmCo5 nanoflakes, with thickness about 50–200 nm and length in the range of 1–2 μm, are prepared. Furthermore, the nanoflakes form “kebab-like” morphology due to the c-axis texture and magnetostatic interaction, which indicates that the easy magnetization direction of as-milled SmCo5 nanoflakes is perpendicular to the surface of the flakes. It is interesting that the nanoflakes with multistep BM shows smaller length and aspect ratio compared with those of usual one step high energy BM6789101112, which is favorable for decreasing the demagnetization fields of SmCo5 nanoflakes.

Bottom Line: The high coercivity of 26.2 kOe for SmCo5 nanoflakes are obtained by multistep (three steps) surfactant-assisted ball milling.The magnetic properties, phase structure and morphology are studied by VSM, XRD and SEM, respectively.The results demonstrate that the three step ball-milling can keep more complete crystallinity (relatively less defects) during the process of milling compared with one step high energy ball-milling, which enhances the texture degree and coercivity.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Magnetism, Institute of Physics, Chinese Academy of Sciences, Beijing, 100190, People's Republic of China.

ABSTRACT
The high coercivity of 26.2 kOe for SmCo5 nanoflakes are obtained by multistep (three steps) surfactant-assisted ball milling. The magnetic properties, phase structure and morphology are studied by VSM, XRD and SEM, respectively. The results demonstrate that the three step ball-milling can keep more complete crystallinity (relatively less defects) during the process of milling compared with one step high energy ball-milling, which enhances the texture degree and coercivity. In addition, the mechanism of coercivity are also studied by the temperature dependence of demagnetization curves for aligned SmCo5 nanoflakes/resin composite, the result indicates that the magnetization reversal could be controlled by co-existed mechanisms of pinning and nucleation.

No MeSH data available.


Related in: MedlinePlus