Synthesis of magnetic alloy-filling carbon nanoparticles in super-critical benzene irradiated with an ultraviolet laser

Abstract

Magnetic nanoparticles are of great importance particularly in the field of biomedicine as well as nanotechnology and nano materials science and technology. Here, we synthesise magnetic alloy-filling carbon nanoparticles (MA@C NPs) via the following two-step procedure; (1) Irradiation of a laser beam of 266 nm wavelength into super-critical benzene, in which both ferrocene and cobaltocene are dissolved, at 290 °C; and (2) annealing of the particles at 600 and 800 °C. We find that the core particles are composed of cobalt (Co), iron (Fe) and oxygen (O) and covered with carbon layers. The structure of the core particles as-synthesised, and annealed at 600 and 800 °C, is, respectively, amorphous, CoFe2O4 and FeCo. We also investigate the viability of L929 cells in the presence of MA@C NPs and find that there is no serious advert effect of the MA@C NPs on the cell viability thanks to the carbon layers covering the core particles. The magnetic properties are well characterised. The saturation and remnant magnetisation and coercivity increase and as a result, the hyperthermic efficiency becomes higher with an increase in the annealing temperature. The further modification of the surface of the present particles with several functional molecules becomes easier due to the carbon layers, which makes the present particles more valuable. It is therefore supposed that the presently synthesised MA@C NPs may well be utilised for nanotechnology-based biomedical engineering; e.g., nano bioimaging, nano hyperthermia and nano surgery.

Ferromagnetically filled carbon nano-onions: the key role of sulfur in dimensional, structural and electric control

“…In particular, these structures have been reported to exhibit giant capacitance and high conductivity (10 S cm −2 ) [10]. In addition to these excellent properties, CNOs have been recently considered important candidates also for magnetic data storage applications as high-density recording media [11][12][13][14][15][16]. Indeed, due to the excellent chemical stability, these structures can be used as nano-sized containers for the encapsulation of specific materials of interest and their protection from oxidation.…”

“…Indeed, due to the excellent chemical stability, these structures can be used as nano-sized containers for the encapsulation of specific materials of interest and their protection from oxidation. In the contest of high-density data storage devices, important attention has been posed on the encapsulation of ferromagnetic single crystals within CNOs [11][12][13][14][15][16][17][18]. Several types of ferromagnets have been encapsulated inside CNOs; these include Fe 3 C, Fe 7 C 3 , Fe 5 C 2 , Fe, Co, Ni, FeCo, CoFe 2 O 4 , FePd 3 and others [11][12][13][14][15][16][17][18].…”

“…In the contest of high-density data storage devices, important attention has been posed on the encapsulation of ferromagnetic single crystals within CNOs [11][12][13][14][15][16][17][18]. Several types of ferromagnets have been encapsulated inside CNOs; these include Fe 3 C, Fe 7 C 3 , Fe 5 C 2 , Fe, Co, Ni, FeCo, CoFe 2 O 4 , FePd 3 and others [11][12][13][14][15][16][17][18]. Thanks to the high magneto-crystalline anisotropy and/or the single magnetic domain critical size dimensionality these materials can indeed exhibit large coercivities and high magnetizations [13][14][15][16].…”

“…Several types of ferromagnets have been encapsulated inside CNOs; these include Fe 3 C, Fe 7 C 3 , Fe 5 C 2 , Fe, Co, Ni, FeCo, CoFe 2 O 4 , FePd 3 and others [11][12][13][14][15][16][17][18]. Thanks to the high magneto-crystalline anisotropy and/or the single magnetic domain critical size dimensionality these materials can indeed exhibit large coercivities and high magnetizations [13][14][15][16]. However, despite the important advancement, several critical challenges remain in order to translate filled CNOs into technological applications.…”

Triggered degradation of 250 μm-thick Mg targets using acetic acid for transient electronic applications

“…On the other hand, Mg and its alloy are useful in various application fields [ 10 , 11 , 12 ]. Especially, Mg has been widely used in transient electronics due to its advantages of easy processing, rapid rates of hydrolysis and biocompatibility [5] .…”