Grain coarsening and its effects on the properties of magnetoelectric 0.675(Pb(Mg1/3Nb2/3)O-3)-0.325PbTiO(2)/CoFe2O4 particulate composites

Journal of Alloys and Compounds Volume: 676 Pages: 80-85 Published: 2016

15 de agosto de 2016 CDMF Artigo 0

SEM-images-of-the-polished-surface-of-PMNPT-CFO — SEM images of the polished surface of PMNPT/CFO particulate composites sintered at 1050 ºC for different sintering times: (a) 1 h; (b) 3 h; (c) 5 h; (d) 7 h; (e) 10 h and (f) 15 h.

Writers: F.L. Zabotto and A.J. Gualdi and P.C. de Camargo and A.J.A. de Oliveira and J.A. Eiras and D. Garcia

Keywords: Grain size effect; Magnetoelectric properties; PMN-PT; Ferroelectric

Abstract: In this work, the influence of the grain coarsening on dielectric, magnetic and magnetoelectric properties of particulate composites constituted by (0.8)0.675(Pb(Mg_1/3Nb_2/3)O₃)–0.325PbTiO₂ – (0.2)CoFe₂O₄ (or PMNPT-CFO) and prepared by solid-state reaction method are presented. The increase of average grain size enhances the tetragonal distortion at the structure of the PMNPT matrix due to control of internal stress of the ferroelectric phase. As consequence, the values of the ε′, g₃₃ and α_ME coefficients reached maximum (ε′ = 25,000, g₃₃ = 53 × 10⁻⁴ Vm/N and α_ME = 14.5 mV/cm Oe) as result of the enhancement of domain structure in the composites. An increase of aprox. 65% in the magnetoeletric coefficient was achieved controlling the microstructure of composites indicating that the magnetoelectric properties in these composites systems could be enhanced by the correct control of the grain coarsening between the phases in particulate composites.

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