Structure and dielectric dispersion in cubic-like 0.5K0.5Na0.5NbO3-0.5Na1/2Bi1/2TiO3 ceramic. (23rd June 2016)

• Record Type: Journal Article
• Authors: Liu, Laijun; Knapp, Michael; Schmitt, Ljubomira Ana; Ehrenberg, Helmut; Fang, Liang; Fuess, Hartmut; Hoelzel, Markus; Hinterstein, Manuel
• Is Part Of: Europhysics letters. Volume 114:Number 4(2016:May)
• Publication Date: 2016-06-23
• Subjects: 77.84.Ek -- 62.40.+i -- 75.10.Nr; Physics -- Periodicals; Electronic journals; 530.05
• DOI: 10.1209/0295-5075/114/47011
• Languages: English
• ISSNs: 0295-5075

Abstract

Abstract: The nature of the cubic-like state in the lead-free piezoelectric ceramics 0.5K0.5 Na0.5 NbO3 -0.5Na1/2 Bi1/2 TiO3 (KNN-50BNT) has been examined in detail by synchrotron x-ray diffraction (SD), selected-area electron diffraction (SAED), neutron diffraction (ND), and temperature-dependent dielectric characterization. The SD pattern of KNN-50BNT presents a pure perovskite structure with pseudocubic symmetry. However, superlattice reflections were observed by SAED and completely indexed by tetragonal symmetry with P 4 bm space group in ND pattern. The relaxor behavior of KNN-50BNT is compared with Pb-based and Ba-based relaxors and discussed in the framework of the Vogel-Fulcher law and the new glass model . The KNN-50BNT ceramic exhibits the strongest dielectric dispersion among them.