Effect of manganese on thermal, structural and magnetic properties of lanthanum modified lead titanate nanoceramics Archana Shukla a,n , Namrata Shukla b , R.N.P. Choudhary c , R. Chaterjee b Q1 a Department of Metallurgical & Materials Engineering, Indian Institute of Technology, Bombay 400076, India b Department of Physics, Indian Institute of Technology Delhi, New Delhi 110016, India c Department of Physics, Institute of Technical Education and Research, Bhubaneswar 751030, India article info Keywords: Nanoceramics Ball milling Ferroelectric Ferromagnetic abstract PbTiO 3 (PT) and La/Mn modified PbTiO 3 (PLMT) nanoceramics were prepared by mechanical alloying and thermal methods. A thermal analysis technique has provided some important clues and guidelines for formation of required compounds and their thermal stability. The formation of single-phase perovskite compounds was confirmed by an X-ray diffraction technique. The field emission scanning electron micrograph of the compounds shows that materials have well-defined granular morphology. La/Mn substitution at Pb/Ti sites reduces the lattice distortion, and decreases ferroelectric phase temperature of lead titanate. Room temperature P–E loop confirms the existence of ferroelectric ordering in the sample. The nonlinear M–H hysteresis loop with small magnetization revealed that a ferromagnetic property is observed in PbTiO 3 due to the substitution of Mn at Ti-sites of PbTiO 3 & 2014 Published by Elsevier B.V. 1. Introduction In the past few years, there has been significant enhancement in the performance and applications of multiferroic materials. Multiferroic materials, which display coexistence of ferromagnet- ism and ferroelectric polarization, have received increased atten- tion because of their interesting and potential properties for multifunctional devices [1]. Unfortunately, multiferroic materials are very rare due to exclusiveness of partially filled atomic orbitals (for magnetic dipoles or moments) and the occurrence of local electric dipoles, which are typically associated with the presence of either empty d-shells and/or an electron lone-pair configuration [2]. Despite this apparently bad compatibility of magnetism and ferroelectri- city, researchers have discovered plenty of systems in which these properties coexist, and many more to come in near future. The structural classification of multiferroic materials includes perovskies, layered perovskites magnetic boracites, hexagonal manganites, rare earth doped manganites, etc. In 1980, Ismailzade et al. [3] reported the presence of linear ME effect in BiFeO 3 ,a perovskite structured compound of antiferromagnetic–ferroelec- tric nature. Its combination with bismuth titanate and barium titanate leads to a family with Aurrivilius structure and shows the coexistence of ferroelectric and ferromagnetic nature up to high temperatures [4]. Spontaneous magnetization in BFO can be induced by the substitution of Fe 3þ by other transition metal ions [5]. Again B- site ions substitution decreases magnetic ordering temperature drastically [6], thus hampering their application at room tempera- ture. Schmid [7] has worked on boracites belonging to the large crystal structure family with a general formula M 3 B 7 O 13 X, where M stands for a bivalent cation of Mn 2 þ , Fe 2 þ , Co 2 þ , Ni 2 þ , Cu 2 þ , Zn 2 þ , etc. and X stands for a monovalent anion like OH À ,F À , Cl À , Br À ,I À or NO 3 À . Typical multiferroics belong to the group of perovskite transi- tion metal oxides. The design and development of perovskites transition-metal oxides have attracted much interest because of their wide variety of physical properties (ferroelectricity, magnet- ism and superconductivity), originating from lattices, spin and orbital couplings [8]. In the perovskite titanate oxides (i.e., PbTiO 3 , BaTiO 3 , etc.) 3d transition metals can be simply substituted at the titanium site due to their close resemblance to the titanium ion in size and valency [9]. The search on the ferromagnetism–ferroelec- tricity phenomenon in the same material began in Russia in the 1950s, with the replacement of some d 0 B cations in ferroelectric perovskite oxides by magnetic d n cations [10]. Kumar and Yadav [11] reported the conversion of enhanced multiferroic properties in Pb (1 Àx) Ba x (Fe 0.5 Ti 0.5 )O 3 . Though some works on multiferroic properties of Mn-substituted PT are available [12] in the literature, detailed studies of dielectric and magnetic properties (with low concentration) of La/Mn modified 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/physb Physica B http://dx.doi.org/10.1016/j.physb.2014.03.011 0921-4526/& 2014 Published by Elsevier B.V. n Corresponding author. Tel.: þ91 99 69461991; fax: þ91 22 2576 7602. E-mail address: ashuklaiitkgp@gmail.com (A. Shukla). Please cite this article as: A. Shukla, et al., Physica B (2014), http://dx.doi.org/10.1016/j.physb.2014.03.011i Physica B ∎ (∎∎∎∎) ∎∎∎–∎∎∎