|
authors |
Coondoo, I; Panwar, N; Rai, R; Amorin, H; Kholkin, AL |
|
nationality |
International |
|
journal |
PHASE TRANSITIONS |
|
author keywords |
lead-free piezoelectric; co-substitution; piezoresponse force microscopy; KNN |
|
keywords |
THIN-FILMS; SOLUTION SYSTEM; PIEZOCERAMICS |
|
abstract |
Polycrystalline samples of lead-free Ca and Ta co-substituted potassium sodium niobate (K0.5Na0.5NbO3, KNN) ceramics have been prepared by solid state reaction technique. X-ray diffraction showed formation of a single-phase perovskite structure with orthorhombic symmetry. Substitution inhibits the grain growth, improves densification and decreases the ferro-paraelectric phase transition temperature. Temperature dependent dielectric permittivity studies demonstrate significant decrease in peak-permittivity values in the substituted samples. Bulk longitudinal piezoelectric coefficient is significantly enhanced, up to approximate to 155 pC/N for (K0.48Na0.48Ca0.02)(Nb0.85Ta0.15O3) as compared to 95 pC/N for pristine KNN ceramic. Local piezoelectric properties have been observed by piezoresponse force microscopy (PFM) technique. Distinct piezocontrast was studied in both vertical and in-plane modes of PFM for all samples. The samples exhibit self-polarization effect in the unpoled state and effective local vertical piezoelectric coefficient was the largest in Ca and Ta co-substituted sample whereas the in-plane piezoelectric coefficient was maximum for Ca-substituted KNN sample. These studies are important for using substituted lead free KNN materials in various piezoelectric applications. |
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publisher |
TAYLOR & FRANCIS LTD |
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issn |
0141-1594 |
|
year published |
2013 |
|
volume |
86 |
|
issue |
11 |
|
beginning page |
1130 |
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ending page |
1140 |
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digital object identifier (doi) |
10.1080/01411594.2013.790032 |
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web of science category |
Crystallography; Physics, Condensed Matter |
|
subject category |
Crystallography; Physics |
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unique article identifier |
WOS:000327475900010
|
