title: Composition-Driven Phase Boundary and Piezoelectricity in Potassium-Sodium Niobate-Based Ceramics.
abstract: The piezoelectricity of (K,Na)NbO3 ceramics strongly depends on the phase boundary types as well as the doped compositions. Here, we systematically studied the relationships between the compositions and phase boundary types in (K,Na) (Nb,Sb)O3-Bi0.5Na0.5AO3 (KNNS-BNA, A=Hf, Zr, Ti, Sn) ceramics; then their piezoelectricity can be readily modified. Their phase boundary types are determined by the doped elements. A rhombohedral-tetragonal (R-T) phase boundary can be driven in the compositions range of 0.035≤BNH≤0.040 and 0.035≤BNZ≤0.045; an orthorhombic-tetragonal (O-T) phase boundary is formed in the composition range of 0.005≤BNT≤0.02; and a pure O phase can be only observed regardless of BNS content (≤0.01). In addition, the phase boundary types strongly affect their corresponding piezoelectricities. A larger d33 (∼440-450 pC/N) and a higher d33* (∼742-834 pm/V) can be attained in KNNS-BNA (A=Zr and Hf) ceramics due to the involvement of R-T phase boundary, and unfortunately KNNS-BNA (A=Sn and Ti) ceramics possess a relatively poor piezoelectricity (d33≤200 and d33*<600 pm/V) due to the involvement of other phase structures (O-T or O). In addition, the underlying physical mechanisms for the relationships between piezoelectricity and phase boundary types were also discussed. We believe that comprehensive research can design more excellent ceramic systems concerning potassium-sodium niobate.
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Ting
authors: T
authors: Zheng
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Jiagang
authors: J
authors: Wu
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Dingquan
authors: D
authors: Xiao
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Jianguo
authors: J
authors: Zhu
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Xiangjian
authors: X
authors: Wang
authors: Department of Materials Science, Sichuan University , Chengdu 610064, P. R. China.|Multidisciplinary Materials Research Center, Frontier Institute of Science and Technology, and State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University , Xi'an 710049, P. R. China.
authors: Xiaojie
authors: X
authors: Lou
keywords: composition design; phase boundary type; piezoelectricity; potassium−sodium niobate; strain