abstract
A current challenge for the fabrication of functional oxide-based devices is related with the need of environmental and sustainable materials and processes. By considering both lead-free ferroelectrics of potassium sodium niobate (K0.5Na0.5NbO3, KNN) and aqueous-based electrophoretic deposition here we demonstrate that an eco-friendly aqueous solution-based process can be used to produce KNN thick coatings with improved electromechanical performance. KNN thick films on platinum substrates with thickness varying between 10 and 15 mu m have a dielectric permittivity of 495, dielectric losses of 0.08 at 1 MHz, and a piezoelectric coefficient d(33) of, similar to 70 pC/N. At T-C these films display a relative permittivity of 2166 and loss tangent of 0.11 at 1 MHz. A comparison of the physical properties between these films and their bulk ceramics counterparts demonstrates the impact of the aqueous-based electrophoretic deposition (EPD) technique for the preparation of lead-free ferroelectric thick films. This opens the door to the possible development of high-performance, lead-free piezoelectric thick films by a sustainable low-cost process, expanding the applicability of lead-free piezoelectrics.
keywords
TEMPERATURE-DEPENDENCE; DIELECTRIC-PROPERTIES; FREE PIEZOCERAMICS; DOMAIN-STRUCTURE; CERAMICS; SUSPENSION; OXIDE; EPD; EVOLUTION
subject category
Chemistry; Materials Science
authors
Mahajan, A; Pinho, R; Dolhen, M; Costa, ME; Vilarinho, PM
our authors
Amit Mahajan
PhD Student
Maria Elisabete Jorge Vieira Costa
Collaborator
Paula Maria Lousada Silveirinha Vilarinho
Vice Director
Rui Manuel de Oliveira Pinho
PhD Studentacknowledgements
This work was developed within the scope of the project CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate cofinanced by FEDER under the PT2020 Partnership Agreement. A.M. acknowledges the FCT for financial support (SFRH/BD/65415/2009). M.D. is thankful to the University of Limoges for financial support within ERASMUS MUNDUS.