Preparation and study of NiFe2O4/SiO2 core–shell nanocomposites

Chaudhuri, Arka; Mandal, Manas K.; Mandal, Kalyan

doi:10.1016/j.jallcom.2009.07.187

Cited by 46 publications

(24 citation statements)

References 20 publications

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“…All the indexed peaks for both samples correspond to crystalline spinel nickel ferrite structure. The XRD of coated sample is noisy due to coating of nanoparticles with amorphous SiO 2 matrix [15,20]. There are no observable diffraction peaks of SiO 2 due to its amorphous nature but we get a hump near angles 2Â between 20 • and 25 • (marked SiO 2 in Fig.…”

Section: Silica Coated Nanoparticles Synthesized Using Sol-gel Methodsmentioning

confidence: 87%

Comparison of surface effects in SiO2 coated and uncoated nickel ferrite nanoparticles

Nadeem

Krenn

Sarwar

et al. 2014

Applied Surface Science

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Section: Silica Coated Nanoparticles Synthesized Using Sol-gel Methodsmentioning

confidence: 87%

Comparison of surface effects in SiO2 coated and uncoated nickel ferrite nanoparticles

Nadeem

Krenn

Sarwar

et al. 2014

Applied Surface Science

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“…14 SiO 2 can be used to prepare nanoparticles with smaller size of single phase because it provides large number of nucleation sites during synthesis process, which finally restrict the growth of nanoparticles. [15][16][17] Consequently, it can be used to control the magnetic properties of multiferroic nanoparticles which will finally affects the magneto-electric coupling. 18 Therefore, it is interesting to study the effect of non-magnetic SiO 2 coating on the structural and magnetic properties CoCr 2 O 4 nanoparticles.…”

Section: Introductionmentioning

confidence: 99%

Role of SiO2 coating in multiferroic CoCr2O4 nanoparticles

et al. 2017

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Effect of silica (SiO2) coating concentration on structural and magnetic properties of multiferroic cobalt chromite (CoCr2O4) nanoparticles have been studied. The nanoparticles with average crystallite size in the range 19 to 28 nm were synthesised by sol-gel method. X-ray diffraction (XRD) analysis has verified the composition of single-phase cubic normal spinel structure of CoCr2O4 nanoparticles. The average crystallite size and cell parameter decreased with increasing SiO2 concentration. TEM image revealed that the shape of nanoparticles was non-spherical. Zero field cooled/field cooled (ZFC/FC) curves revealed that nanoparticles underwent a transition from paramagnetic (PM) state to collinear short-range ferrimagnetic (FiM) state, and this PM–FiM transition temperature decreased from 101 to 95 K with increasing SiO2 concentration or decreasing crystallite size. A conical spin state at Ts = 27 K was also observed for all the samples which decreased with decreasing average crystallite size. Low temperature lock-in transition was also observed in these nanoparticles at 12 K for uncoated nanoparticles which slightly shifted towards low temperature with decreasing average crystallite size. Saturation magnetization (Ms) showed decreasing trend with increasing SiO2 concentration, which was due to decrease in average crystallite size of nanoparticles and enhanced surface disorder in smaller nanoparticles. The temperature dependent AC-susceptibility also showed the decrease in the transition temperature (Tc), broadening of the Tc peak and decrease in magnetization with increasing SiO2 concentration or decreasing average crystallite size. In summary, the concentration of SiO2 has significantly affected the structural and magnetic properties of CoCr2O4 nanoparticles.

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“…One of the most important groups of magnetic nanoparticles is ferrite which has a very high magnetization value at room temperature [7]. Manganese ferrite (MnFe 2 O 4 ) as a superparamagnetic nanoparticle has a very high magnetization capacity owing to its large magnetic spin magnitude [8].…”

Section: Introductionmentioning

confidence: 99%