Tuning the ferroelectric transition and magnetic ordering by the polar Ba0.1Sr0.9TiO3 substitution in the multiferroic (1-x) Ba0.1Sr0.9TiO3 - xBiFeO(3) (0.2 = x = 0.8) solid solution

摘要

Chemical substitution is an effective method for tailoring the electrical and magnetic properties of functional materials. In this work, (1-x)Ba0.1Sr0.9TiO3 - xBiFeO(3) (0.2 = x = 0.8) ceramics were prepared by the modified Pechini method. X-ray diffraction patterns manifest that the samples undergo a gradual structural transformation from rhombohedral phase to tetragonal phase with increasing the content of Ba0.1Sr0.9TiO3 (BST). Dielectric properties show that T-C can be modulated by the doping level of BST in a wide range from 885 K to 260 K accompanied by the ferroelectric transformation from non-relaxor type to relaxor type ferroelectricity. The room temperature ferroelectricity, ferromagnetism and intrinsic magnetodielectric are observed in the BiFeO3-rich samples. Magnetization and magnetodielectric measurement both show that the spin cycloid is destroyed by the substitution of BST and the critical field for the transition from spiral to antiferromagnetic collinear magnetic structure decreases with increasing the amount of BST. These findings manifest that this materials are quite promising for potential applications in BFO-based magnetoelectric devices and electrocaloric cooling technologies. (c) 2018 Elsevier B.V. All rights reserved.