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Subject: Basic Sciences × Author: Joshi, Hema × End date: 2022 × Type: Thesis × Thesis Type: M.Sc ×
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    ThesisItemOpen Access
    Investigation of structural, optical and ferroelectric behaviour of NIFE2O4 and YMNO3 composites
    (G.B. Pant University of Agriculture and Technology, Pantnagar, District Udham Singh Nagar, Uttarakhand. PIN - 263145, 2022-09) Joshi, Hema; Dixit, Gagan
    Magnetoelectric multiferroic materials are characterized by the property of ME coupling which allows the manipulation of magnetisation in these materials by applying an external electric field and vice-versa. Due to this property, multiferroic materials are widely used in technological applications like sensors, memory devices, microwave applications, solar cells, energy harvesting etc. These materials are being continuously studied to obtain better magnetic and electric properties and higher value of ME coupling coefficient. In the present work composites of NiFe2O4 (NFO) and YMnO3 (YMO), xNiFe2O4/(1-x)YMnO3 [x = 0.25 and 0.50] have been prepared by mixing NiFe2O4 and YMnO3 powders. Different measurement techniques; XRD, UV-Vis spectroscopy, P-E loop measurement and VSM have been used to study structural, optical, ferroelectric and magnetic properties of the composites and the pure samples. Coexistence of both the ferrite and ferroelectric phase in the composites was confirmed by XRD analysis. Variation in lattice constant and crystallite size confirm that NFO lattice is more susceptible for change in structural parameters than the YMO lattice. The band gap values for all the samples determined using UV-Vis spectra varied in the range 1.4 to 1.75 eV. Saturation magnetization for pure NiFe2O4 was found to be highest and its value was 46.17emu/g. The composites show ferromagnetic ordering with saturation magnetization decreasing with increase in concentration of ferroelectric phase in the composites. P-E hysteresis loop measurement indicates resistive type behavior of composites as well as pure YMnO3. High conductivity of the samples was the reason for this poor ferroelectric nature of the samples.