Effects of nano-sized BCZT on structure and electrical properties of KNN-based lead-free piezoceramics

Effects of nano-sized BCZT on structure and electrical properties of KNN-based lead-free... The (1 − x)(Li0.03Na0.5K0.47)(Nb0.92Sb0.05Ta0.03)O3–xBa0.85Ca0.15Zr0.1Ti0.9O3 (LNKNST–BCZT, x = 0, 0.5, 1.5, 2.5, and 3.5%) lead-free piezoceramics were synthesized by the conventional solid-state reaction method with adding nano-sized Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) powder to investigate their influences on crystal structure and electrical properties. The X-ray diffraction (XRD) analysis reveals that all the sintered LNKNST–BCZT ceramics exhibit pure perovskite structure with the mainly rhombohedral (R) phase or the coexistence of rhombohedral (R) phase and tetragonal (T) phase. The composition of the LNKNST–1.5%BCZT ceramics locates around the critical point, i.e., the ceramics changing from the coexistence of rhombohedral (R) phase and tetragonal (T) phase to purely rhombohedral (R) phase, and presents the most densified microstructure morphology, which can be confirmed further by the field emission scanning electron microscope (FESEM) observation. There are two dielectric anomalies in the temperature dependent dielectric properties curves of the LNKNST–BCZT ceramics, which correlate with the ferroelectric rhombohedral (R) phase changing to the ferroelectric tetragonal (T) phase, and then to the paraelectric cubic (C) phase. Both the Curie–Weiss law and the power law fittings confirm the diffuse phase transition ferroelectrics characteristic of the LNKNST–1.5%BCZT ceramics, which is considered as correlating with the polar nanoregions (PNRs). Due to the densification effect caused by the chosen amount of nano-sized BCZT doping and the construction of R–T polymorphic phase boundary, the LNKNST–1.5%BCZT ceramics exhibit the best ferroelectric and piezoelectric properties. The complex impedance spectroscopy analysis confirms that the extrinsic electrical conduction mechanism at high temperatures is dominated by the oxygen vacancies induced by the evaporation of the alkali metals during sintering. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Journal of Materials Science: Materials in Electronics Springer Journals

Effects of nano-sized BCZT on structure and electrical properties of KNN-based lead-free piezoceramics

Loading next page...
 
/lp/springer_journal/effects-of-nano-sized-bczt-on-structure-and-electrical-properties-of-4GUhqYQhfD
Publisher
Springer US
Copyright
Copyright © 2017 by Springer Science+Business Media, LLC, part of Springer Nature
Subject
Materials Science; Optical and Electronic Materials; Characterization and Evaluation of Materials
ISSN
0957-4522
eISSN
1573-482X
D.O.I.
10.1007/s10854-017-8389-x
Publisher site
See Article on Publisher Site

Abstract

The (1 − x)(Li0.03Na0.5K0.47)(Nb0.92Sb0.05Ta0.03)O3–xBa0.85Ca0.15Zr0.1Ti0.9O3 (LNKNST–BCZT, x = 0, 0.5, 1.5, 2.5, and 3.5%) lead-free piezoceramics were synthesized by the conventional solid-state reaction method with adding nano-sized Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) powder to investigate their influences on crystal structure and electrical properties. The X-ray diffraction (XRD) analysis reveals that all the sintered LNKNST–BCZT ceramics exhibit pure perovskite structure with the mainly rhombohedral (R) phase or the coexistence of rhombohedral (R) phase and tetragonal (T) phase. The composition of the LNKNST–1.5%BCZT ceramics locates around the critical point, i.e., the ceramics changing from the coexistence of rhombohedral (R) phase and tetragonal (T) phase to purely rhombohedral (R) phase, and presents the most densified microstructure morphology, which can be confirmed further by the field emission scanning electron microscope (FESEM) observation. There are two dielectric anomalies in the temperature dependent dielectric properties curves of the LNKNST–BCZT ceramics, which correlate with the ferroelectric rhombohedral (R) phase changing to the ferroelectric tetragonal (T) phase, and then to the paraelectric cubic (C) phase. Both the Curie–Weiss law and the power law fittings confirm the diffuse phase transition ferroelectrics characteristic of the LNKNST–1.5%BCZT ceramics, which is considered as correlating with the polar nanoregions (PNRs). Due to the densification effect caused by the chosen amount of nano-sized BCZT doping and the construction of R–T polymorphic phase boundary, the LNKNST–1.5%BCZT ceramics exhibit the best ferroelectric and piezoelectric properties. The complex impedance spectroscopy analysis confirms that the extrinsic electrical conduction mechanism at high temperatures is dominated by the oxygen vacancies induced by the evaporation of the alkali metals during sintering.

Journal

Journal of Materials Science: Materials in ElectronicsSpringer Journals

Published: Dec 14, 2017

References

You’re reading a free preview. Subscribe to read the entire article.


DeepDyve is your
personal research library

It’s your single place to instantly
discover and read the research
that matters to you.

Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.

All for just $49/month

Explore the DeepDyve Library

Unlimited reading

Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.

Stay up to date

Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.

Organize your research

It’s easy to organize your research with our built-in tools.

Your journals are on DeepDyve

Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.

All the latest content is available, no embargo periods.

See the journals in your area

DeepDyve Freelancer

DeepDyve Pro

Price
FREE
$49/month

$360/year
Save searches from Google Scholar, PubMed
Create lists to organize your research
Export lists, citations
Access to DeepDyve database
Abstract access only
Unlimited access to over
18 million full-text articles
Print
20 pages/month
PDF Discount
20% off