Unusual dielectric properties of hollow magnesium ferrite nanospheres: a potential lightweight microwave absorber

Saha, P and Rakshit, R and Gorai, A and Mandal, D and Mandal, K (2022) Unusual dielectric properties of hollow magnesium ferrite nanospheres: a potential lightweight microwave absorber. In: Journal of Materials Science, 57 (7). pp. 4569-4582.

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Abstract

We present a combination of dielectric and magnetic experimental signatures on MgxFe3-xO4 (x = 0.0, 0.2, 0.3, 0.4 and 1.0) nano-hollow spheres (NHSs) magnetic semiconductor system. Interestingly, Mg0.3Fe2.7O4 NHSs with the maximum value of room temperature dielectric permittivity behave as negative index material in the vicinity of metamagnetic transition. Detailed study reveals that high dipolar fluctuation-assisted back-scattering under strong spin�polaron coupling results in negative dielectric index, while metamagnetic transition takes place due to the ferromagnetic arrangement of spins by overcoming the super-exchange interaction in Mg0.3Fe2.7O4 NHSs. Finally, an excellent electromagnetic wave absorbing efficiency with reflection loss (RL)= - 53.8 dB in the 1�20 GHz range is achieved by utilizing high room temperature dielectric and magnetic loss, and the hollow interior of Mg0.3Fe2.7O4 NHSs, opening up a plethora of interesting possibilities in lightweight shielding devices, and waveguides for microwave applications. © 2022, The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Item Type:	Journal Article
Publication:	Journal of Materials Science
Publisher:	Springer
Additional Information:	The copyright for this article belongs to Springer
Keywords:	Backscattering; Electromagnetic waves; Magnesium; Magnesium compounds; Magnetic semiconductors; Magnetism, Back scattering; Dielectric permittivities; Dielectrics property; Magnesium ferrite; Metamagnetic transitions; Microwave absorbers; Nano hollow spheres; Negative-index-materials; Semiconductor systems; Spin polaron, Permittivity
Department/Centre:	Division of Chemical Sciences > Solid State & Structural Chemistry Unit
Date Deposited:	21 Feb 2022 12:05
Last Modified:	21 Feb 2022 12:05
URI:	http://eprints.iisc.ac.in/id/eprint/71407

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