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Synthesis of magnetic nanofibers using femtosecond laser material processing in air.

Alubaidy MA, Venkatakrishnan K, Tan B - Nanoscale Res Lett (2011)

Bottom Line: The nanofibers diameter varies between 30 and 70 nm and they are mixed with nanoparticles.X-ray diffraction (XRD) analysis revealed metallic and oxide phases in the nanostructure.The growth of magnetic nanostructure is highly recommended for the applications of magnetic devices like biosensors and the results suggest that the pulsed-laser method is a promising technique for growing nanocrystalline magnetic nanofibers and nanoparticles for biomedical applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M3N 2H8, Canada. venkat@ryerson.ca.

ABSTRACT
In this study, we report formation of weblike fibrous nanostructure and nanoparticles of magnetic neodymium-iron-boron (NdFeB) via femtosecond laser radiation at MHz pulse repetition frequency in air at atmospheric pressure. Scanning electron microscopy (SEM) analysis revealed that the nanostructure is formed due to aggregation of polycrystalline nanoparticles of the respective constituent materials. The nanofibers diameter varies between 30 and 70 nm and they are mixed with nanoparticles. The effect of pulse to pulse separation rate on the size of the magnetic fibrous structure and the magnetic strength was reported. X-ray diffraction (XRD) analysis revealed metallic and oxide phases in the nanostructure. The growth of magnetic nanostructure is highly recommended for the applications of magnetic devices like biosensors and the results suggest that the pulsed-laser method is a promising technique for growing nanocrystalline magnetic nanofibers and nanoparticles for biomedical applications.

No MeSH data available.


Related in: MedlinePlus

MFM image of NdFeB nanofibrous structures formed upon irradiation of laser at 26 MHz pulse repetition rate.
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Figure 5: MFM image of NdFeB nanofibrous structures formed upon irradiation of laser at 26 MHz pulse repetition rate.

Mentions: During ablation, the ionized material is removed away from the surface in the form of expanding high pressure plasma. The temperature of the plasma is above the melting temperature and hence Curie temperature of the magnet. Thus the irradiated spot and the surrounding area where temperatures above 400°C will be demagnetized while the rest of the sample remains magnet. The plasma remains confined close to the specimen surface at atmospheric pressure. Condensation of vapor in the plume leads to the generation of nanoparticles which move in the direction where the paramagnetization potential energy is minimized [24]. The nanoparticles travelled perpendicular to the direction of the magnetic field and then aggregate and get deposited on the surface of the specimen [25]. The generated nanofibers remagnetized when its temperature reduced below the Curie temperature of the sample to form magnetic nanofibers. The total magnetization of a nanofiber is given by the vectorial sum of all single magnetic moments of the atoms [24]. As for the atomic magnetic moments in generated nanofibers, the average magnetization will be zero in the absence of magnetic field since all magnetic moments are randomly directed in space. When a magnetic field is applied by the substrate, the magnetic moments will orient in the direction of the field and give rise to a net magnetization of the nanofibers. Magnetic field microscopy, from NT-MDT, (MFM) image of the weblike nanofibers structures generated at 26 MHz is shown in Figure 5. The NdFeB nanofibers exhibit magnetic properties (darker parts) as shown in the MFM image of Figure 5 which are distinguishable from the background (brighter parts).


Synthesis of magnetic nanofibers using femtosecond laser material processing in air.

Alubaidy MA, Venkatakrishnan K, Tan B - Nanoscale Res Lett (2011)

MFM image of NdFeB nanofibrous structures formed upon irradiation of laser at 26 MHz pulse repetition rate.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211468&req=5

Figure 5: MFM image of NdFeB nanofibrous structures formed upon irradiation of laser at 26 MHz pulse repetition rate.
Mentions: During ablation, the ionized material is removed away from the surface in the form of expanding high pressure plasma. The temperature of the plasma is above the melting temperature and hence Curie temperature of the magnet. Thus the irradiated spot and the surrounding area where temperatures above 400°C will be demagnetized while the rest of the sample remains magnet. The plasma remains confined close to the specimen surface at atmospheric pressure. Condensation of vapor in the plume leads to the generation of nanoparticles which move in the direction where the paramagnetization potential energy is minimized [24]. The nanoparticles travelled perpendicular to the direction of the magnetic field and then aggregate and get deposited on the surface of the specimen [25]. The generated nanofibers remagnetized when its temperature reduced below the Curie temperature of the sample to form magnetic nanofibers. The total magnetization of a nanofiber is given by the vectorial sum of all single magnetic moments of the atoms [24]. As for the atomic magnetic moments in generated nanofibers, the average magnetization will be zero in the absence of magnetic field since all magnetic moments are randomly directed in space. When a magnetic field is applied by the substrate, the magnetic moments will orient in the direction of the field and give rise to a net magnetization of the nanofibers. Magnetic field microscopy, from NT-MDT, (MFM) image of the weblike nanofibers structures generated at 26 MHz is shown in Figure 5. The NdFeB nanofibers exhibit magnetic properties (darker parts) as shown in the MFM image of Figure 5 which are distinguishable from the background (brighter parts).

Bottom Line: The nanofibers diameter varies between 30 and 70 nm and they are mixed with nanoparticles.X-ray diffraction (XRD) analysis revealed metallic and oxide phases in the nanostructure.The growth of magnetic nanostructure is highly recommended for the applications of magnetic devices like biosensors and the results suggest that the pulsed-laser method is a promising technique for growing nanocrystalline magnetic nanofibers and nanoparticles for biomedical applications.

View Article: PubMed Central - HTML - PubMed

Affiliation: Department of Mechanical Engineering, Ryerson University, 350 Victoria Street, Toronto, ON, M3N 2H8, Canada. venkat@ryerson.ca.

ABSTRACT
In this study, we report formation of weblike fibrous nanostructure and nanoparticles of magnetic neodymium-iron-boron (NdFeB) via femtosecond laser radiation at MHz pulse repetition frequency in air at atmospheric pressure. Scanning electron microscopy (SEM) analysis revealed that the nanostructure is formed due to aggregation of polycrystalline nanoparticles of the respective constituent materials. The nanofibers diameter varies between 30 and 70 nm and they are mixed with nanoparticles. The effect of pulse to pulse separation rate on the size of the magnetic fibrous structure and the magnetic strength was reported. X-ray diffraction (XRD) analysis revealed metallic and oxide phases in the nanostructure. The growth of magnetic nanostructure is highly recommended for the applications of magnetic devices like biosensors and the results suggest that the pulsed-laser method is a promising technique for growing nanocrystalline magnetic nanofibers and nanoparticles for biomedical applications.

No MeSH data available.


Related in: MedlinePlus