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Effects of GeO 2 Addition on Sintering and Properties of (K 0.5 Na 0.5 )NbO 3 Ceramics
Author(s) -
Chen Kepi,
Zhang Fangli,
Jiao Yanlin,
Li Dianshan,
Tang Jing,
Gao Feng,
An Linan
Publication year - 2016
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/jace.14162
Subject(s) - sintering , materials science , natural bond orbital , ceramic , piezoelectricity , dopant , dielectric , analytical chemistry (journal) , mineralogy , doping , phase (matter) , composite material , optoelectronics , chemistry , density functional theory , computational chemistry , chromatography , organic chemistry
Lead‐free (K 0.5 Na 0.5 )NbO 3 ( KNN ) piezoelectric ceramics doped with different amounts of GeO 2 were prepared and characterized. GeO 2 was found to effectively improve the sinterability and piezoelectric properties of the material. The improvement in the sinterability is ascribed to the formation of a liquid phase, which decreased the sintering temperature from 1080°C to 1010°C. The improvement in the properties is attributed to the replacement of Nb 5+ with Ge 4+ to form acceptor dopants. The following optimized properties were obtained from the KNN ceramic with 0.75 wt% GeO 2 : piezoelectric constant ( d 33 ) = 126 pC /N, planar electromechanical coupling coefficient ( k p ) = 42.8%, mechanical quality factor ( Q m ) = 140, and dielectric loss (tanδ) = 3.8%.