Morphotropic phase boundary and electrical properties of K{sub 1-x}Na{sub x}NbO{sub 3} lead-free ceramics

Journal Article · Mon Jan 26 00:00:00 EST 2009 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.3076105· OSTI ID:21175931

Yejing, Dai; Xiaowen, Zhang ^[1]; Kepi, Chen ^[2]

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1. Department of Materials Science and Engineering, State Key Laboratory of New Ceramics and Fine Processing, Tsinghua University, Beijing 100084 (China)
2. Key Laboratory of Condition Monitoring and Control for Power Plant Equipment (Ministry of Education), North China Electric Power University, Beijing 102206 (China)

Lead-free K{sub 1-x}Na{sub x}NbO{sub 3} ceramics with x=0.48-0.54 were prepared by a conventional solid-state reaction method to investigate the influence of the K/Na ratio on phase structures and electrical properties. The results suggest that a typical morphotropic phase boundary exists at x=0.52-0.525, separating the monoclinic and orthorhombic phases. The sample with the composition near x=0.52 shows the maximum values of the piezoelectric constant (d{sub 33}=160 pC/N) and the electromechanical coupling coefficient (k{sub t}=47%). The results provide a helpful guidance to consider the optimal ratio of K to Na for designing and developing new (K,Na)NbO{sub 3}-based ceramics.

• OSTI ID: 21175931
• Journal Information: Applied Physics Letters, Vol. 94, Issue 4; Other Information: DOI: 10.1063/1.3076105; (c) 2009 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CERAMICS
DIELECTRIC MATERIALS
MONOCLINIC LATTICES
NIOBATES
ORTHORHOMBIC LATTICES
PERMITTIVITY
PHASE TRANSFORMATIONS
PIEZOELECTRICITY
POLARIZATION
POTASSIUM COMPOUNDS
SINTERING
SODIUM COMPOUNDS