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Title: Piezoelectric properties of Li- and Ta-modified (K{sub 0.5}Na{sub 0.5})NbO{sub 3} ceramics

Abstract

Lead-free, potassium sodium niobate piezoelectric ceramics substituted with lithium (K{sub 0.5-x/2},Na{sub 0.5-x/2},Li{sub x})NbO{sub 3} or lithium and tantalum (K{sub 0.5-x/2},Na{sub 0.5-x/2},Li{sub x})(Nb{sub 1-y},Ta{sub y})O{sub 3} have been synthesized by traditional solid state sintering. The compositions chosen are among those recently reported to show high piezoelectric properties [Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, and M. Nakamura, Nature (London) 42, 84 (2004); Y. Guo, K. Kakimoto, and H. Ohsato, Appl. Phys. Lett. 85, 4121 (2004); Mater. Lett. 59, 241 (2005)]. We show that high densities and piezoelectric properties can be obtained for all compositions by pressureless sintering in air, without cold isostatic pressing, and without any sintering aid or special powder treatment. Resonance and converse piezoelectric (strain-field) measurements show a thickness coupling coefficient k{sub t} of 53% and converse piezoelectric coefficient d{sub 33} around 200 pm/V for the Li-substituted ceramics, and a k{sub t} of 52% and d{sub 33} over 300 pm/V for the Li- and Ta-modified samples. The unipolar strain-field hysteresis is small and comparable to that measured under similar conditions in hard Pb(Zr,Ti)O{sub 3}. A peak of piezoelectric properties can be noted close to the morphotropic phase boundary. These ceramics look verymore » promising as possible, practicable, lead-free replacements for lead zirconate titanate.« less

Authors:
; ; ;  [1]
  1. Ceramics Laboratory, Ecole Polytechnique Federale de Lausanne-EPFL, Lausanne (Switzerland)
Publication Date:
OSTI Identifier:
20706411
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 87; Journal Issue: 18; Other Information: DOI: 10.1063/1.2123387; (c) 2005 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; AIR; CERAMICS; DIELECTRIC MATERIALS; HYSTERESIS; LITHIUM COMPOUNDS; NIOBATES; PIEZOELECTRICITY; POTASSIUM COMPOUNDS; POWDERS; PZT; RESONANCE; SINTERING; SODIUM COMPOUNDS; STRAINS; TANTALUM COMPOUNDS; THICKNESS

Citation Formats

Hollenstein, Evelyn, Davis, Matthew, Damjanovic, Dragan, and Setter, Nava. Piezoelectric properties of Li- and Ta-modified (K{sub 0.5}Na{sub 0.5})NbO{sub 3} ceramics. United States: N. p., 2005. Web. doi:10.1063/1.2123387.
Hollenstein, Evelyn, Davis, Matthew, Damjanovic, Dragan, & Setter, Nava. Piezoelectric properties of Li- and Ta-modified (K{sub 0.5}Na{sub 0.5})NbO{sub 3} ceramics. United States. doi:10.1063/1.2123387.
Hollenstein, Evelyn, Davis, Matthew, Damjanovic, Dragan, and Setter, Nava. Mon . "Piezoelectric properties of Li- and Ta-modified (K{sub 0.5}Na{sub 0.5})NbO{sub 3} ceramics". United States. doi:10.1063/1.2123387.
@article{osti_20706411,
title = {Piezoelectric properties of Li- and Ta-modified (K{sub 0.5}Na{sub 0.5})NbO{sub 3} ceramics},
author = {Hollenstein, Evelyn and Davis, Matthew and Damjanovic, Dragan and Setter, Nava},
abstractNote = {Lead-free, potassium sodium niobate piezoelectric ceramics substituted with lithium (K{sub 0.5-x/2},Na{sub 0.5-x/2},Li{sub x})NbO{sub 3} or lithium and tantalum (K{sub 0.5-x/2},Na{sub 0.5-x/2},Li{sub x})(Nb{sub 1-y},Ta{sub y})O{sub 3} have been synthesized by traditional solid state sintering. The compositions chosen are among those recently reported to show high piezoelectric properties [Y. Saito, H. Takao, T. Tani, T. Nonoyama, K. Takatori, T. Homma, T. Nagaya, and M. Nakamura, Nature (London) 42, 84 (2004); Y. Guo, K. Kakimoto, and H. Ohsato, Appl. Phys. Lett. 85, 4121 (2004); Mater. Lett. 59, 241 (2005)]. We show that high densities and piezoelectric properties can be obtained for all compositions by pressureless sintering in air, without cold isostatic pressing, and without any sintering aid or special powder treatment. Resonance and converse piezoelectric (strain-field) measurements show a thickness coupling coefficient k{sub t} of 53% and converse piezoelectric coefficient d{sub 33} around 200 pm/V for the Li-substituted ceramics, and a k{sub t} of 52% and d{sub 33} over 300 pm/V for the Li- and Ta-modified samples. The unipolar strain-field hysteresis is small and comparable to that measured under similar conditions in hard Pb(Zr,Ti)O{sub 3}. A peak of piezoelectric properties can be noted close to the morphotropic phase boundary. These ceramics look very promising as possible, practicable, lead-free replacements for lead zirconate titanate.},
doi = {10.1063/1.2123387},
journal = {Applied Physics Letters},
number = 18,
volume = 87,
place = {United States},
year = {Mon Oct 31 00:00:00 EST 2005},
month = {Mon Oct 31 00:00:00 EST 2005}
}
  • Reddish orange-emitting 0.948(K{sub 0.5}Na{sub 0.5})NbO{sub 3}-0.052LiSbO{sub 3}-xmol%Sm{sub 2}O{sub 3} (KNN-5.2LS-xSm{sub 2}O{sub 3}) lead-free piezoelectric ceramics with good piezoelectric properties were fabricated in this study, and the photoluminescence and electrical properties of the ceramics were systematically studied. Results showed that Sm{sub 2}O{sub 3} substitution into KNN-5.2LS induces a phase transition from the coexistence of orthorhombic and tetragonal phases to a pseudocubic phase and shifts the polymorphic phase transition (PPT) to below room temperature. The temperature stability and fatigue resistance of the modified ceramics were significantly improved by Sm{sub 2}O{sub 3} substitution. The KNN-5.2LS ceramic with 0.4 mol. % Sm{sub 2}O{sub 3} exhibitedmore » temperature-independent properties (25–150 °C), fatigue-free behavior (up to 10{sup 6} cycles), and good piezoelectric properties (d{sub 33}{sup * }= 230 pm/V, d{sub 33} = 176 pC/N, k{sub p} = 35%). Studies on the photoluminescence properties of the samples showed strong reddish-orange emission upon blue light excitation; these emission intensities were strongly dependent on the doping concentration and sintering temperature. The 0.4 mol. % Sm{sub 2}O{sub 3}-modified sample exhibited temperature responses over a wide temperature range of 10–443 K. The maximum sensing sensitivity of the sample was 7.5 × 10{sup −4} K at 293 K, at which point PPT occurred. A relatively long decay lifetime τ of 1.27–1.40 ms and a large quantum yield η of 0.17–0.19 were obtained from the Sm-modified samples. These results suggest that the KNN-5.2LS-xSm{sub 2}O{sub 3} system presents multifunctional properties and significant technological potential in novel multifunctional devices.« less
  • The CaTiO{sub 3}-modified [(K{sub 0.5}Na{sub 0.5}){sub 0.96}Li{sub 0.04}](Nb{sub 0.91}Sb{sub 0.05}Ta{sub 0.04})O{sub 3} lead-free piezoelectric ceramics were prepared using normal sintering for improving the temperature stability of (K{sub 0.5}Na{sub 0.5})NbO{sub 3}-based ceramics. The effects of the CaTiO{sub 3} on the temperature stability and piezoelectric properties of the ceramics were systematically studied. These results show that the CaTiO{sub 3}-modified [(K{sub 0.5}Na{sub 0.5}){sub 0.96}Li{sub 0.04}](Nb{sub 0.91}Sb{sub 0.05}Ta{sub 0.04})O{sub 3} lead-free piezoelectric ceramics possess good temperature stability in the polymorphic phase transition below room temperature, and also exhibit high piezoelectric properties (d{sub 33}=263 pC/N and k{sub p}=50%) when the ceramics were poled at anmore » optimum poling temperature. These results indicate that the ceramic is a promising candidate material for lead-free piezoelectric ceramics.« less
  • We report the piezoelectric and ferroelectric properties of (Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}){sub x}-(BaTiO{sub 3}){sub y}-(Na{sub 0.5}K{sub 0.5}NbO{sub 3}){sub 1-x-y} ceramics for Na{sub 0.5}K{sub 0.5}NbO{sub 3} rich end of composition (x, y {<=} 0.04 mol. %). These compositions were found to exhibit significantly improved thermal stability of piezoresponse. Variation of dielectric constant as a function of temperature revealed that orthorhombic-tetragonal (T{sub o-t}) and tetragonal-cubic (T{sub c}) transition temperatures for these compositions were in the vicinity of 0 Degree-Sign C and 330 Degree-Sign C, respectively. Dynamic scaling and temperature dependent X-ray diffraction analysis were conducted. Results are discussed in terms of intrinsicmore » and extrinsic contributions to the piezoelectric response explaining the temperature dependent behavior.« less
  • Dense K{sub 4}CuNb{sub 8}O{sub 23} modified (Na{sub 0.5}K{sub 0.5})NbO{sub 3} (NKN:KCN) ceramics were synthesized by using conventional oxide mixing process. The maximum mechanical quality factor Q{sub m} of NKN:KCN ceramics reaches up to 1150, the piezoelectric constant d{sub 33} and the planar electromechanical coefficient k{sub p} still maintain relatively high levels, which are about 100 pC/N and 40%, respectively. Middle frequency (455 kHz) lead-free resonators were fabricated by using NKN:KCN, and remarkable improvements in resonance characteristics were found by KCN doping.
  • Lead-free piezoelectric ceramics (1-x)(Na{sub 0.5}K{sub 0.5})NbO{sub 3}-xLiNbO{sub 3} {l_brace}[Li{sub x}(Na{sub 0.5}K{sub 0.5}){sub 1-x}]NbO{sub 3}{r_brace} (x=0.04-0.20) have been synthesized by an ordinary sintering technique. The materials with perovskite structure is orthorhombic phase at x{<=}0.05 and becomes tetragonal phase at x{>=}0.07, a phase K{sub 3}Li{sub 2}Nb{sub 5}O{sub 15} with tetragonal tungsten bronze structure begins to appear at x=0.08 and becomes dominant with increasing the content of LiNbO{sub 3}. A morphotropic phase boundary between orthorhombic and tetragonal phases is found in the composition range 0.05<x<0.07. Analogous to Pb(Zr,Ti)O{sub 3}, the piezoelectric and electromechanical properties are enhanced for compositions near the morphotropic phase boundary.more » Piezoelectric constant d{sub 33} values reach 200-235 pC/N. Electromechanical coefficients of the planar mode and the thickness mode reach 38%-44% and 44%-48%, respectively. The Curie temperatures (T{sub C}) of [Li{sub x}(Na{sub 0.5}K{sub 0.5}){sub 1-x}]NbO{sub 3} (x=0.04-0.20) are in the range of 452-510 deg. C, at least 100 deg. C higher than that of conventional Pb(Zr,Ti)O{sub 3}. Our results show that [Li{sub x}(Na{sub 0.5}K{sub 0.5}){sub 1-x}]NbO{sub 3} is a good lead-free high-temperature piezoelectric ceramic.« less