Premium
Microstructure evolution and electromechanical properties of (K,Na) NbO 3 ‐based thick films
Author(s) -
Mercier Hugo,
Levassort Franck,
Uršič Hana,
Kuscer Danjela
Publication year - 2020
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.17146
Subject(s) - materials science , microstructure , sintering , coalescence (physics) , composite material , dielectric , grain size , substrate (aquarium) , melting point , electrophoretic deposition , optoelectronics , coating , oceanography , physics , astrobiology , geology
This study investigated an unconventional method of electrophoretic deposition (EPD) for the processing of environmentally benign (K 0.5 Na 0.5 ) 0.99 Sr 0.005 NbO 3 (KNNSr) thick films on Pt/alumina substrate. EPD allows rapid, economical, and low‐waste processing of thick films and thus offers an integration advantage for electronics manufacturing. To understand the functional response of the KNNSr thick films, the effect of the sintering temperature and atmosphere on their structure, microstructure, and electromechanical properties was investigated. KNNSr thick films densify in constrained conditions in a very narrow temperature range only a few 10°C below the melting temperature of 1140°C. Up to 1100°C the relative density increases to 80%, upon further heating to 1110°C we observed only the grain growth and pore coalescence. The densification is not affected significantly by the atmosphere. The local domain structure of 25‐33 μm thick KNNSr films was similar, while the dielectric and electromechanical properties increased with the increasing sintering temperature. KNNSr thick film sintered at 1100°C has a thickness‐coupling factor k t of 0.4, comparable to that of bulk. The results reveal that the EPD enables the economic processing of high‐performance thick films on complex‐shape substrates that are difficult to fabricate using conventional thick‐film methods.