Ferrites; nanocomposites; M-H method; microwave sintering; dielectric properties; magnetic propertie
Department of Physics, Osmania University, Hyderabad 500007, India
Adv. Mater. Lett., 2013, 'ICNANO 2011', 4 (1), pp 99-105
Publication Date (Web): Oct 14, 2012
Copyright © IAAM-VBRI Press
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.
Ferrites, nanocomposites, M-H method, microwave sintering, dielectric properties, magnetic properties.