Induced anisotropic behavior and enhanced electrical properties on hot-pressed strontium barium niobate ceramics

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• 作者：Hui Chen^a ; ^b ; Shaobo Guo^a ; Chunhua Yao^a ; Xianlin Dong^a ; Chaoliang Mao^a ; Genshui Wang^a ; ^{genshuiwang@mail.sic.ac.cn}
• 关键词：A. Hot-pressing ; C. Pyroelectric properties ; D. Strontium barium niobate ; D. Lead-free ceramics
• 刊名：Ceramics International
• 出版年：2017
• 出版时间：March 2017
• 年：2017
• 卷：43
• 期：4
• 页码：3610-3615
• 全文大小：1617 K
• 卷排序：43

文摘

Sr0.30Ba0.70Nb2O6 (SBN30) ferroelectric ceramics were fabricated by conventional sintering (CS) and by hot-pressing sintering (HP) and their crystal structure, microstructure, dielectric, ferroelectric and pyroelectric properties were studied and compared. Preferred orientation of the HP ceramics was detected through X-ray diffraction. Dense microstructure virtually free of pores has been achieved in HP samples. Moreover, the HP samples manifested prominent anisotropy in electrical properties. Besides, the relative permittivity (εr), saturated polarization (Ps), pyroelectric coefficient (p) in the direction perpendicular to the pressing axis were much higher than those of the randomly oriented CS samples. The HP samples sintered under 200 MPa show excellent pyroelectric properties in the direction perpendicular to the pressing axis, with pyroelectric coefficient of 2.38×10−8C/cm2K and pyroelectric figure of merit of Fi=1.13 pm/V, Fv=1.89 m2/C and Fd=0.63 μPa−1/2，which roughly triple the values obtained in CS samples. These results indicate that hot-pressing is a viable option for accessing single-crystal-like anisotropy as well as enhanced electrical properties in polycrystalline ceramics, thus unveiling the distinctive potential of HP SBN30 ceramics for infrared detector applications.