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Hydrothermal Synthesis and Spark Plasma Sintering of (K, Na)NbO 3 Lead‐Free Piezoceramics
Author(s) -
Liu Nan,
Wang Ke,
Li JingFeng,
Liu Zonghuai
Publication year - 2009
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2009.03126.x
Subject(s) - spark plasma sintering , natural bond orbital , hydrothermal circulation , materials science , piezoelectricity , sintering , hydrothermal synthesis , ferroelectricity , perovskite (structure) , mineralogy , phase (matter) , ceramic , analytical chemistry (journal) , dielectric , chemical engineering , crystallography , composite material , chemistry , optoelectronics , organic chemistry , chromatography , density functional theory , computational chemistry , engineering
A facile hydrothermal route was adopted for synthesis of lead‐free piezoceramics (K, Na)NbO 3 powders. The influences of temperature and KOH/NaOH concentration on the resultant powders were investigated. Although two similar perovskite phases appeared when K/Na ratio tended toward 1:1, the two‐phase coexistence tendency was weakened by increasing hydrothermal reaction temperature, and consequently only one phase could be obtained after spark plasma sintering. Reasonably good ferroelectric and piezoelectric properties were obtained for the samples after postannealing, whose piezoelectric constant ( d 33 ) reached 135 pC/N. The optimal remnant polarization ( P r ) and mechanical quality factor ( Q m ) were 26.2 μC/cm 2 and 164, respectively, which were both twice as much as those of the samples using powders prepared from solid‐state reaction.