Actuators 2015, 4(2), 99-113; doi:10.3390/act4020099
Ferroelectric KNNT Fibers by Thermoplastic Extrusion Process: Microstructure and Electromechanical Characterization
1
Empa - Swiss Federal Laboratories for Materials Science and Technology, High Performance Ceramics, Überlandstrasse 129, CH-8600 Dübendorf, Switzerland
2
Changwon National University, Gyeong-Nam 641-773, South Korea
†
These authors contributed equally to this work.
*
Authors to whom correspondence should be addressed.
Academic Editor: Delbert Tesar
Received: 20 March 2015 / Revised: 30 April 2015 / Accepted: 5 May 2015 / Published: 8 May 2015
(This article belongs to the Special Issue Feature Papers)
Abstract
B-site substitution in KNN with tantalum results in a higher d33 and dielectric constant. This higher value makes KNNT interesting for lead-free actuator applications. KNNT fibers with diameters of 300 and 500 μm have been extruded and sintered at 1200 °C in a KNNT-enriched atmosphere. Subsequently, the influence of fiber diameter on the microstructure (porosity and grain size) was investigated. The measurements revealed that with decreasing fiber diameter, the porosity increases, whereas the grain size decreases. The influence of these microstructural differences on the piezoelectric properties was evaluated using a novel characterization procedure for single fibers. The larger diameter fibers show an increase in the electromechanical properties measured, i.e., d33, tanδ, Pr, Ec and the free longitudinal fiber displacement, when compared to smaller diameter fibers. The lower alkali losses result in a larger grain size, a higher density during sintering and lead to higher electromechanical properties. View Full-TextKeywords:
KNNT; fibers; dielectric constant; fiber diameter
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. (CC BY 4.0).
Scifeed alert for new publications
Never miss any articles matching your research from any publisher- Get alerts for new papers matching your research
- Find out the new papers from selected authors
- Updated daily for 49'000+ journals and 6000+ publishers
- Define your Scifeed now
Share & Cite This Article
MDPI and ACS Style
Lusiola, T.; Hussain, A.; Kim, M.H.; Graule, T.; Clemens, F. Ferroelectric KNNT Fibers by Thermoplastic Extrusion Process: Microstructure and Electromechanical Characterization. Actuators 2015, 4, 99-113.
Related Articles
Article Metrics
Comments
[Return to top]
Actuators
EISSN 2076-0825
Published by MDPI AG, Basel, Switzerland
RSS
E-Mail Table of Contents Alert