D1619095416

Effect of Zn and Mn Substitution on Structural, Dielectric, Magnetic and Optical Properties of Multiferroic CoFe2O4-BaTiO3 Core-Shell Type Composites
Sourav Sarkar¹, J. Shah², R. K. Kotnala³, M. C. Bhatnagar^4
1Sourav Sarkar, Department of Physics, Indian Institute of Technology, Delhi (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, Delhi (New Delhi). India.
Manuscript received on 20 September 2016 | Revised Manuscript received on 30 September 2016 | Manuscript published on 30 September 2016 | PP: 16-26 | Volume-5 Issue-4, September 2016 | Retrieval Number: D1619095416©BEIESP
Open Access | Ethics and Policies | Cite | Mendeley | Indexing and Abstracting
© 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: In this paper, we have reported the synthesis of Zn and Mn substituted cobalt ferrite by chemical co-precipitation method and used it as core material in barium titanate sol to finally prepare core-shell type composite material. Amount of ferrite was varied in the final composite samples from 30% to 50%. X-ray diffraction show prominent spinel and perovskite peaks corresponding to ferrite and titanate phases respectively. HRTEM micrographs reveal core-shell type nature with presence of a well-defined interface. Our proposed substitutions increase the resistivity of pure cobalt ferrite by one order which has been verified through I-V measurement. SEM micrographs show dense microstructure and particle formation of both phases in the composites. Substitution of Zn at the site of Co is supported by the peak shift in Attenuated Total Reflection Fourier Transform Infrared (ATR-FTIR) spectroscopy. Maxwell Wagner relaxation phenomena at the interface and hopping conduction in ferrites explain both frequency and temperature variation of dielectric parameters. Substitution of Zn and Mn result in superparamagnetic type behavior with coercively  few Oe and very negligible remnant magnetization (MR). Photoluminescence (PL) spectra show slight decrease in energy band gap of ferrite as a result of these substitutions.
Keywords: Sol-gel process (A); Composites (B); Dielectric properties (C); Optical properties (C)
Scope of the Article: Optical Oscillator