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7241239 
Journal Article 
Antiferroelectricity in new silver niobate lead-free antiferroelectric ceramics (1-x)AgNbO3-xCaZrO(3) (x=0.00-0.01) 
Xu, Y; Guo, Yan; Liu, Q; Bai, J; Huang, J; Lin, L; Lu, S; , 
2019 
Yes 
Journal of Alloys and Compounds
ISSN: 0925-8388 
ELSEVIER SCIENCE SA 
LAUSANNE 
469-476 
WOS:000458608600053 
The critical need for clean energy has led to the development of lead-free electroceramics. However, lead-free antiferroelectrics seldom have been reported because of the difficulties in materials fabrication and their low electrical performance. In this work, we successfully synthesized lead-free antiferroelectric ceramics (1-x)AgNbO3-xCaZrO(3) (x = 0.00-0.01) using the solid state reaction method in flowing oxygen (O-2) atmosphere. Calcium zirconate (CaZrO3) dopant effectively stabilized the antiferroelectricity of silver niobate (AgNbO3) by dramatically decreasing the tolerance factor t. Additionally, we identified an orthorhombic Pbcm structure similar to that of pure AgNbO3. With the introduction of CaZrO3, phase transition temperatures M-1-M-2, M-2-M-3 and the freezing temperature T-f decreased. The shift of the M-1-M-2 phase transition temperature and T-f was the result of the restriction of the M-1 phase due to CaZrO3 substitution. The compositions of x < 0.001 displayed a double hysteresis loop with a raised critical field E-F. However, when the doping concentration exceeded 0.002, the double hysteresis loop with a higher polarization could not be obtained until the breakdown strength of E-B exceeded 200 kV/cm because of the tremendously enhanced free energy barrier between the virgin antiferroelectric state and the field-induced ferroelectric state. We also evaluated the polarization hysteresis loops are also evaluated at temperatures up to 100 degrees C for the compositions x= 0.00-0.005. With an elevated temperature, at which the free energy barrier was reduced, the double hysteresis loop was obtained at a lower electric field when compared with that at room temperature for the compositions x= 0.004 and 0.005. These results demonstrated that by adjusting the tolerance factor t and average electronegativity difference X, the antiferroelectricity could be predicted in AgNbO3-based lead-free solid solution systems, thus providing a new strategy for designing a new class of antiferroelectric materials. (C) 2018 Elsevier B.V. All rights reserved.