화학공학소재연구정보센터
Materials Research Bulletin, Vol.68, 331-335, 2015
Surface spins enhanced magnetoelectric coefficient and impedance spectroscopy of BaFe0.01Ti0.99O3 and BaFe0.015Ti0.985O3 nanorods
Multiferroic BaFe0.01Ti0.99O3 (BFT1) and BaFe0.015Ti0.985O3 (BFT15) nanorods were prepared by a sol-gel synthesis and annealed at 700 degrees C/2 h. The tetragonal phase and nano dimensions of BFT samples are identified by X-ray diffraction and transmission electron microscopy. The enhancement in ferroelectricity depends upon low porosity, tetragonal phase, space charge field, larger surface area and oriented growth. The ferromagnetism depends upon partially filled inner shells, surface spins and oxygen vacancies. The magnetoelectric coefficient is explained on the basis of surface spins, short-range interactions near surface boundary, compressive stress and twin structure contributed by nano grains which can reside stress near grain boundaries. The frequency dependent real (Z') and imaginary (Z '') parts of impedance spectra are confirmed by the variations that observed in dielectric properties. The values of resistance of grain boundaries, R-gb is higher than grains, R-g indicating that the effect of grain boundaries is dominant in BFT nanorods. (C) 2015 Elsevier Ltd. All rights reserved.