J Supercond Nov Magn (2017) 30:1317–1325 DOI 10.1007/s10948-016-3928-x ORIGINAL PAPER Evidence for Room-Temperature Weak Ferromagnetic and Ferroelectric Ordering in Magnetoelectric Pb(Fe 0.634 W 0.266 Nb 0.1 )O 3 Ceramic Shidaling Matteppanavar 1 · Shivaraja I 1 · Sudhindra Rayaprol 2 · Basavaraj Angadi 1 · Balaram Sahoo 3 Received: 30 September 2016 / Accepted: 22 November 2016 / Published online: 5 December 2016 © Springer Science+Business Media New York 2016 Abstract We report the evidence of weak ferromagnetic and ferroelectric ordering in polycrystalline Pb(Fe 0.634 W 0.266 Nb 0.1 )O 3 (0.8(PbFe 2/3 W 1/3 )O 3 –0.2Pb(Fe 1/2 Nb 1/2 ) O 3 ) (PFWN) ceramic at room temperature. The Pb(Fe 0.634 W 0.266 Nb 0.1 )O 3 solid solution synthesized through the columbite method. The obtained single-phase Pb(Fe 0.634 W 0.266 Nb 0.1 )O 3 ceramic was subjected to X-ray diffrac- tion, neutron diffraction, magnetization, M¨ ossbauer spec- troscopy, and ferroelectric measurements. The X-ray diff- raction and neutron diffraction pattern confirms the for- mation of single phase without any traces of pyrochlore phases, having cubic structure with Pm-3m space group. The Rietveld refinements were carried out on both pat- terns, and ND data confirms the G-type antiferromagnetic structure with propagation vector (k = 1/2, 1/2, and 1/2). However, along with the antiferromagnetic ordering of the Fe spins, we also observed the existence of weak ferro- magnetism. This result was confirmed through (i) a clear opening of hysteresis (M H) loop, (ii) bifurcation of the field-cooled (FC) and zero-field-cooled (ZFC) sus- ceptibilities, (iii) spin-glass behavior, and (iv) M¨ ossbauer spectroscopy. Basavaraj Angadi brangadi@gmail.com 1 Department of Physics, Bangalore University, Jnanabharathi Campus, Bangalore, 560056, India 2 UGC-DAE-Consortium for Scientific Research, Mumbai Centre, BARC Campus, Mumbai, 400085, India 3 Materials Research Centre, Indian Institute of Science, Bangalore, 560012, India Keywords Multiferroics · Columbite method · Neutron diffraction · Spin glassy · Weak ferromagnetism · Ferroelectric 1 Introduction Pb-based multiferroics [13] are promising candidates for the design and synthesis of multifunctional materials. They are important for their unique and strong coupling of elec- tric, magnetic, and structural order parameters, giving rise to simultaneous ferroelectricity, ferromagnetism, and fer- roelasticity [4]. This is of great interest to study these compounds from a fundamental perspective, as well as for potential applications in magnetoelectric and magnetoelas- tic devices. In these systems, the interplay and competitions between spins, dopant charge carriers, the degree of free- dom of orbital, and lattice symmetry lead to a variety of couplings and phase transitions [4]. Currently, most of the research on single-phase multiferroics is concentrated on lowering sintering temperatures as much as possible, without much change in the properties of the materials. Among them, lead iron tungstate—Pb(Fe 2/3 W 1/3 )O 3 (PFW) and lead iron niobate—Pb(Fe 1/2 Nb 1/2 )O 3 (PFN) are widely studied multiferroic properties independently because of their unique multiferroic proprieties [57]. The PFW is known as a multiferroic material with a com- plex perovskite-type structure (ABB?O 3 ) in which Fe 3+ and W 6+ are randomly distributed at the octahedral B-site positions and presents a relaxor ferroelectric and antiferro- magnetic ordering. The ferroelectric Curie temperature (T C ) was reported to occur between 150 and 200 K [5]. PFN undergoes a normal ferroelectric phase transition which occurs around 380 K and an antiferromagnetic phase tran- sition at 155 K [6, 7]. Unfortunately, these materials suffer