<abstract xmlns="http://www.w3.org/1999/xhtml">Manganese substituted cobalt ferrite (Co1–xMnxFe2O4 with x = 0, 0.3, 0.5, 0.7 and 1) nanopowders were synthesized by chemical coprecipitation method. The synthesized magnetic nanoparticles were investigated by various characterization techniques, such as X-ray diffraction (XRD), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) and thermogravimetric and differential thermal analysis (TG/DTA). The XRD results confirmed the presence of cubic spinel structure of the prepared powders and the average crystallite size of magnetic particles ranging from 23 to 45 nm. The VSM results showed that the magnetic properties varied with an increase in substituted manganese while SEM analysis showed the change in the morphology of obtained magnetic nanoparticles. The TG/DTA analysis indicated the formation of crystalline structure of the synthesized samples. The heat transfer rate was measured in specially prepared magnetic nanofluids (nanoparticles dispersed in carrier fluid transformer oil) as a function of time and temperature in presence of external magnetic fields. The experimental analysis indicated enhanced heat transfer rate of the magnetic nanofluids which depended upon the strength of external magnetic field and chemical composition.</abstract>

Manganese substituted cobalt ferrite (Co1–xMnxFe2O4 with x = 0, 0.3, 0.5, 0.7 and 1) nanopowders were synthesized by chemical coprecipitation method. The synthesized magnetic nanoparticles were investigated by various characterization techniques, such as X-ray diffraction (XRD), vibrating sample magnetometry (VSM), scanning electron microscopy (SEM) and thermogravimetric and differential thermal analysis (TG/DTA). The XRD results confirmed the presence of cubic spinel structure of the prepared powders and the average crystallite size of magnetic particles ranging from 23 to 45 nm. The VSM results showed that the magnetic properties varied with an increase in substituted manganese while SEM analysis showed the change in the morphology of obtained magnetic nanoparticles. The TG/DTA analysis indicated the formation of crystalline structure of the synthesized samples. The heat transfer rate was measured in specially prepared magnetic nanofluids (nanoparticles dispersed in carrier fluid transformer oil) as a function of time and temperature in presence of external magnetic fields. The experimental analysis indicated enhanced heat transfer rate of the magnetic nanofluids which depended upon the strength of external magnetic field and chemical composition.

Experimental investigation on heat transfer rate of Co–Mn ferrofluids in external magnetic field

Anna University Chennai: University College of Engineering-Ariyalur, Department of Physics, Ariyalur-621704, India

Anna University Chennai: University College of Engineering-Pattukkottai, Department of Physics, Rajamadam-614701, Thanjavur, India

Anna University Chennai: University College of Engineering-Ariyalur, Department of EEE, Ariyalur-621704, India

Anna University Chennai: University College of Engineering-Kanchipuram, Department of Physics, Kanchipuram-631552, India

Materials Science-Poland

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Manganese substituted cobalt ferrite (Co1–xMnxFe2O4 with x = 0, 0.3, 0.5, 0.7 and 1) nanopowders were synthesized by chemical coprecipitation method. The...

No	Sample	Lattice constant [Å]
1	CoFe₂O₄	8.397
2	Co_0.7Mn_0.3Fe₂O₄	8.424
3	Co_0.5Mn_0.5Fe₂O₄	_8.421
4	Co_0.3Mn_0.7Fe₂O₄	8.466
5	MnFe₂O₄	8.493

Experimental investigation on heat transfer rate of Co–Mn ferrofluids in external magnetic field

Article Category: Research Article

Published Online: May 24, 2016

Page range: 427 - 436

Received: Nov 25, 2015

Accepted: Feb 28, 2016

DOI: https://doi.org/10.1515/msp-2016-0048

Keywords
magnetic nanoparticles, coprecipitation, magnetic fluids, rate of heat transfer, carrier fluid

© Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Summary of lattice constant values [ Å] for Co1–xMnxFe2O4 with x varying from 0.0, 0.3, 0.5, 0.7 and 1.0.

Experimental investigation on heat transfer rate of Co–Mn ferrofluids in external magnetic field

Article Category: Research Article

Published Online: May 24, 2016

Page range: 427 - 436

Received: Nov 25, 2015

Accepted: Feb 28, 2016

DOI: https://doi.org/10.1515/msp-2016-0048

Keywordsmagnetic nanoparticles, coprecipitation, magnetic fluids, rate of heat transfer, carrier fluid

© Wroclaw University of Technology

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Fig. 1

Fig. 2

Fig. 3

Fig. 4

Fig. 5

Fig. 6

Fig. 7

Fig. 8

Summary of lattice constant values [ Å] for Co1–xMnxFe2O4 with x varying from 0.0, 0.3, 0.5, 0.7 and 1.0.

Keywords
magnetic nanoparticles, coprecipitation, magnetic fluids, rate of heat transfer, carrier fluid