An Extensive Study of Structural, Dielectric, Magnetic and Optical Properties of Multiferroic CoFe2O4-BaTiO3 and CoFe1.7Mn0.3O4-BaTiO3 Core-Shell Type Composites
Sourav Sarkar1, J. Shah2, R. K. Kotnala3, M. C. Bhatnagar4

1Sourav Sarkar, Department of Physics, Indian Institute of Technology, (New Delhi), India.
2Dr. Jyoti Shah, Department of Material Physics and Engineering, National Physical Laboratory, (New Delhi), India.
3Dr. R. K. Kotnala, Department of Material Physics and Engineering, National Physical Laboratory, (New Delhi), India.
4Dr. Mukesh Chander Bhatnagar, Department of Physics, Indian Institute of Technology, (New Delhi), India.
Manuscript received on 10 July 2016 | Revised Manuscript received on 21 July 2016 | Manuscript Published on 30 July 2016 | PP: 38-44 | Volume-6 Issue-2, July 2016 | Retrieval Number: B2338076216/16©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: Multiferroic CoFe2O4 -BaTiO3 and CoFe1.7Mn0.3O4 – BaTiO3 core-shell type composites (CFO-BTO and CFMO-BTO) were synthesized by conventional wet chemical method which combined two processes: co–precipitation method and sol–gel technique. X-ray diffraction (XRD) analysis confirms presence of both phases and average crystallite sizes for them were calculated to be in the range 15 – 30 nm. HRTEM micrographs ensure proposed core-shell like structure and verify estimated particle size from XRD data. No impurity other than the constituent elements has been found in the EDX spectra of individual phases as well as composites. SEM images of the powder form suggest presence of two different phases in the composites while images of the pellet forms show particle formation of both phases with dense microstructure. Variation of dielectric parameters with temperature at different frequencies yielded expected results with some interesting response around magnetic Curie temperature (Tc) for CFMO-BTO composite. Magnetic hysteresis loops were plotted for all these samples by applying a dc magnetic field in the range -5000 Oe to +5000 Oe. They show expected ferromagnetic behavior. Photoluminescence (PL) data was acquired using a laser excitation source of 266 nm. Emission peaks corresponding to individual phases (CFO, CFMO and BTO) as well as the composites were recorded and studied for the first time in core–shell composites.
Keywords: I—Composites, Dielectric Properties, Optical Properties, Sol-gel Processes.

Scope of the Article: Composite Materials