|
authors |
Kaushal, A; Olhero, SM; Singh, B; Zamiri, R; Saravanan, V; Ferreira, JMF |
|
nationality |
International |
|
journal |
RSC ADVANCES |
|
keywords |
BARIUM-TITANATE; GRAIN-SIZE; TEMPERATURE; CERAMICS; BEHAVIOR; INDENTATION; STABILITY; HARDNESS |
|
abstract |
We report on the successful aqueous processing of a lead free piezoelectric 0.5Ba(Zr0.2Ti0.8)O-3-0.5( Ba0.7Ca0.3)TiO3 (BZT-BCT) composition with the final functional properties of the materials unaffected by the various processing steps involved. X-ray diffraction results show a single tetragonal perovskite crystalline phase for the as-received sintered BZT-BCT powder. The purity of the perovskite phase for BZT-BCT powder was found to be controlled even after ageing the material in water for 24 h as a successful surface treatment against hydrolysis. An aqueous suspension of surface treated BZT-BCT powder with 50 vol% solid loading was successfully transformed into micro-sized granules via a freeze granulation (FG) method. Various structural, electrical and mechanical properties of sintered BZT-BCT-FG and BZT-BCT-NG ceramics consolidated from freeze granulated and non-granulated (NG) powders, respectively, were measured. The dielectric constant (epsilon(r)) values of the BZT-BCT-FG sample were found to be higher, with lower dielectric loss (tan delta) values in comparison with those of a sample prepared from the BZT-BCT-NG powder at all temperatures and with all frequency ranges tested. Nanoindentation results revealed that the ability to oppose deformation was nearly 10-fold higher for BZT-BCT-FG (6.93 GPa) than for BZT-BCT-NG ceramics (543 MPa). The functional properties of BZT-BCT- FG samples confirmed the benefits of the aqueous processing approach in comparison with traditional dry pressing. |
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publisher |
ROYAL SOC CHEMISTRY |
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issn |
2046-2069 |
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year published |
2014 |
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volume |
4 |
|
issue |
51 |
|
beginning page |
26993 |
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ending page |
27002 |
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digital object identifier (doi) |
10.1039/c4ra03172e |
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web of science category |
Chemistry, Multidisciplinary |
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subject category |
Chemistry |
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unique article identifier |
WOS:000338640200057
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