Structural and Electric Evidence of Ferrielectric State in Pb2MnWO6 Double Perovskite System

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• 作者：Fabio Orlandi ; Lara Righi ; Riccardo Cabassi ; Davide Delmonte ; Chiara Pernechele ; Fulvio Bolzoni ; Francesco Mezzadri ; Massimo Solzi ; Marco Merlini ; Gianluca Calestani
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：October 6, 2014
• 年：2014
• 卷：53
• 期：19
• 页码：10283-10290
• 全文大小：481K
• ISSN：1520-510X

文摘

In this paper we describe the new ferri-electric compound Pb₂MnWO₆ (PMW), a double perovskite that can be considered as a novel structural prototype showing complex nuclear structure and interesting electric properties. According to single-crystal synchrotron data, PMW crystallizes in the noncentrosymmetric polar group Pmc2₁, in which the two symmetry-independent lead atoms give rise to a ferrielectric arrangement. The accurate crystallographic characterization indicates the presence of a complex distortion of the perovskite lattice driven by the local instability induced by the 6s² lone pair of the lead atoms. These peculiar structural features are confirmed by the complete electrical characterization of the system. Dielectric and transport measurements indicate an insulating character of the sample, while pyroelectric measurements point out a ferrielectric state characterized by different contributions. The magnetic transition at 45 K is accompanied by a magnetostrictive effect indicating a probable spin鈥搇attice coupling. The characterizations carried out on PMW, showing the evidence of a coexistence of antiferromagnetism and ferrielectricity at low temperature, could lead to the definition of a new class of multiferroic materials.