Microwave-hydrothermal Synthesis Of CoFe2O4-TiO2 Nanocomposites

Department of Physics, Osmania University, Hyderabad 500007, India

Adv. Mater. Lett., 2013, 'ICNANO 2011', 4 (1), pp 99-105

DOI: 10.5185/amlett.2013.icnano.130

Publication Date (Web): Oct 14, 2012

Copyright © IAAM-VBRI Press

Email: ramanasarabu@yahoo.com

Abstract

The nanocomposites of x TiO₂+(1-x)CoF₂O₄ (≤x≤1) powders were synthesized using microwave-hydrothermal method at a low temperature of 165°C/45min. The synthesized powder was characterized by using XRD, TEM, FTIR and DSC. The particle size was obtained from TEM study varies from 18nm to 34nm for all the nanopwders. DSC curve of composites shows no anatase to rutile phase transformation. As synthesized powder was densified using a microwave sintering method at 500°C/30min. In the XRD patterns of sintered composite samples, no peaks other than TiO₂ and CoFe₂O₄ were observed. The grain sizes of the composites have been estimated from SEM pictures and they are in between 54 to 78nm. The dielectric properties were measured in the frequency range of 100 Hz to 1 MHz. The frequency variation of dielectric properties is understood with the help of Maxwell–Wagner type of interfacial polarization, which is in agreement with Koop’sphenomenological theory. The thermal variation of dielectric constant and loss studies were also undertaken at a constant frequency of 1kHz. Magnetic properties were also measured on all the composite samples at room temperature. The saturation magnetization (Ms) of the samples decreases with an increase of TiO₂ content in CoFe₂O₄.

Keywords

Ferrites, nanocomposites, M-H method, microwave sintering, dielectric properties, magnetic properties.