Enhanced magneto-capacitance in Sr2+ modified BiFeO3�PbTiO3 solid solutions

Kumar, N and Narayan, B and Singh, A and Kumar, S (2020) Enhanced magneto-capacitance in Sr2+ modified BiFeO3�PbTiO3 solid solutions. In: Materials Chemistry and Physics, 252 .

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Abstract

Polycrystalline ceramics of 0.7BiFeO3-0.3 Pb(1-x)SrxTiO3 compositions with x = 0, 0.2, 0.4, 0.6, 0.8 and 1.0 were successfully synthesized by solid state reaction method. The structural, microstructural, ferroelectric, magnetic, dielectric and magnetocapacitive properties have been investigated. X-Ray diffraction analysis using Rietveld refinement revealed the existence of multiphase region with rhombohedral (R3c) and tetragonal (P4mm) polymorphs for x = 0, 0.2, 0.4, 0.6 & 0.8 and single phase with cubic crystallinity for x = 1.0 with Pm3�m space group. SEM micrographs depicted dense microstructure with non-uniform grains. Except x = 0, pinched ferroelectric loops have been observed for x = 0.2, 0.4, 0.6, 0.8 and 1.0 with low remnant polarization. Sr2+ substitution enhanced the magnetization by suppressing antiferromagnetic spin cycloid of BiFeO3 and the maximum value of remnant was found to be 9.98 memu/g for x = 1.0. Room temperature dielectric studies revealed that the dielectric constant decreases with increasing Sr2+ content in the composition. The magnetoelectric coupling was measured through observing the relative change in dielectric constant induced by applied magnetic field (Magnetocapacitance: MC). The maximum value of magnetocapacitance was found to be 0.88 for the composition with x = 0.6. The magnetic field induced fractional dielectric constant can also be expressed as MC ~ γM2 using Ginzburg�Landau theory and the linear fitting gave the value of positive value of magnetoelectric interaction constant, γ = 3.79, 2.08 and 1.76 for x = 0, 0.06 and 1.0, respectively. © 2020 Elsevier B.V.

Item Type:	Journal Article
Publication:	Materials Chemistry and Physics
Publisher:	Elsevier Ltd
Additional Information:	Copy right for this article belongs to Elsevier Ltd
Keywords:	Crystallinity; Ferroelectricity; Iron compounds; Lead titanate; Magnetic fields; Rietveld refinement; Solid state reactions; X ray powder diffraction, Antiferromagnetic spins; Applied magnetic fields; Dielectric studies; Magnetocapacitance; Magnetoelectric couplings; Polycrystalline ceramics; Remnant polarizations; Solid state reaction method, Bismuth compounds
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	10 Nov 2020 09:35
Last Modified:	10 Nov 2020 09:35
URI:	http://eprints.iisc.ac.in/id/eprint/65961

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