Contents lists available at ScienceDirect Ceramics International journal homepage: www.elsevier.com/locate/ceramint Structural modification and evaluation of dielectric and ferromagnetic properties of Ce-modified BiFeO 3 –BaTiO 3 ceramics Mst. Sharmin Mostari a,* , Nurul Islam b , Md. Abdul Matin c a Department of Glass & Ceramic Engineering, Rajshahi University of Engineering & Technology, Rajshahi, 6204, Bangladesh b Department of Mechanical Engineering, Rajshahi University of Engineering & Technology, Rajshahi, 6204, Bangladesh c Department of Glass and Ceramic Engineering, Bangladesh University of Engineering and Technology, Dhaka, 1000, Bangladesh ARTICLE INFO Keywords: Rietveld analysis Polygonal grain Ferromagnetic property Crystallite size ABSTRACT An investigation on Rare earth constituent Ce incorporated BiFeO 3 –BaTiO 3 ceramics has been focused in the present study. The ceramic samples of (Bi 0 . 7 Ba 0.3 ) 1-x Ce x (Fe 0 . 7 Ti 0.3 )O 3 (x =0–0.12) were formulated adopting the cost-effective solid-state sintering method. The influence of aliovalent Ce ions on the structural, micro- structural, dielectric, ferromagnetic, and optical properties of BiFeO 3 –BaTiO 3 was evaluated in this paper. The coexistence of the Tetragonal and the Rhombohedral phases was established by the Rietveld refinement process. The refined crystallographic parameters showed maximum cell volume (V cell ) and the highest percentage of the Rhombohedral phase for x = 0.06; and consequently, the ceramic exhibited the topmost dielectric constant of 946 at x = 0.06. The scanning electron microscopy of the samples revealed the manifestation of polygonal grain morphology. Besides, remarkably improved ferromagnetic properties were evinced for Ce doped ceramics. The magnitude of saturation (M s ) and remnant (M r ) magnetizations were boosted from 0 emu/g and 0.0019 emu/g to 0.9186 emu/g and 0.3745 emu/g respectively with increasing x from 0 to 0.12. Additionally, the optical band gaps of all the samples were evaluated and found to be in the range of 2.941–3.077 eV. 1. Introduction The co-existence of any two from the ferromagnetic, ferroelectric and ferroelastic physiognomies in perovskite materials has created great interest among the researchers and scientists in the last few decades due to the emergence of multifunctional devices which have made human life and technological approach easier. Such types of combined-order parameters play a pivotal role in sophisticated devices such as spintronics, actuators, sensors, transducers, novel memory de- vices, and quantum electromagnets [1–3]. Among the perovskite ma- terials, BiFeO 3 (BF) is the only candidate which presents significantly high Curie temperature (T C = 810–860 °C) and antiferromagnetic Néel temperature (T N = 325–397 °C)); hence, BF remains most attractive in the high-temperature applications [4–6]. But the applicability of BF has been questioned for the obstacles found in its pathway and these ob- stacles include low insulation and high electronic leakage current, presence of impurity phase, high-temperature phase decomposition. As a result, the unsaturated ferroelectric loop and high dielectric loss have appeared in BF [7,8]. To suppress all of these incompatibilities, in- vestigation on the solid solution of BF with suitable perovskite structure (s), e.g., BaTiO 3 (BT), has come to a focal point. An in-depth literature survey of BiFeO 3 –BaTiO 3 (BFBT) materials demonstrates a superior resistivity than BF, and this superior resistivity still remains unsatisfactory. As the Morphotropic Phase Boundary (MPB) of BFBT (67BF-33BT) resides in the domain of ferromagnetic counterpart [9,10], it is expected to provide outstanding ferro- magnetism and ferroelectricity. Notably, most of the investigations re- veal high dielectric loss/rare saturated P-E loop/weak piezo –response [11] attributed by the evaporative Bi 3+ and the oxidation-reduction tactic of iron. Besides, weak ferromagnetism was witnessed in BFBT due to the clampdown of the canted cycloidal spin structure originated from the Dzyaloshinskii-Moriya interaction [12]. The previous studies re- vealed that the partial substitution of lanthanides (La, Ce, Nd, Gd, Eu, Er, etc.) in BiFeO 3 confirmed an antiferro-ferromagnetic transition [13]; hence, several investigations have been attempted to understand their effects on the functional characteristics of BFBT [14–16]. Qi et al. [14] reported Rare Earth (RE) La modified BFBT with good structural stability, considerable dielectric constant, and high remnant magnetization of 0.666 emu/g at 0.4 mol% of doping. Similarly, the introduction of Eu in BFBT altered the values of M s and M r positively by 165% and 141%, respectively [15]. Moreover, co-dopings such as Dy-La [17] and Dy–Pr [18] were also studied to obtain improved multiferroic https://doi.org/10.1016/j.ceramint.2020.03.131 Received 26 October 2019; Received in revised form 12 February 2020; Accepted 12 March 2020 * Corresponding author. E-mail address: sharmin015@gmail.com (M.S. Mostari). Ceramics International xxx (xxxx) xxx–xxx 0272-8842/ © 2020 Elsevier Ltd and Techna Group S.r.l. All rights reserved. Please cite this article as: Mst. Sharmin Mostari, Nurul Islam and Md. Abdul Matin, Ceramics International, https://doi.org/10.1016/j.ceramint.2020.03.131