Effects of A-Site Nonstoichiometry on Dielectric and Piezoelectric Properties of Pb-Free (Na0.53+x K0.47)(Nb0.55Ta0.45)O3 Ceramics

Lee, J. H.; Ryu, G. H.; Do, D.; Song, Tae-Ho; Kim, M. H.; Park, T. G.; Kim, W. J.; Kim, S. S.; Sung, Y. S.; Baik, Sunggi

doi:10.1080/10584587.2012.664077

Cited by 4 publications

(3 citation statements)

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“…In the next step, the powder mixture was milled with yttria-stabilized zirconia balls in anhydrous alcohol for 24 h. After drying at 90 °C in a dry oven, the powders were calcined at 850 °C for 4 h in air with an intermediate ball milling and drying process, in order to produce powders of a uniform particle size. The powder processing is described in more detail in Lee et al [11].…”

Section: Methodsmentioning

confidence: 99%

“…In order to reduce the material volatilization during sintering of KNNT fibers, 1 g of KNNT powder was placed on the inside of the alumina crucible lid, creating a KNNT-rich atmosphere. The KNNT fibers were sintered at 1200 °C for 4 h [11].…”

Section: Methodsmentioning

confidence: 99%

“…These properties make Ta an ideal candidate to act as a B-site substituent in KNN, as shown by Lee et al, who produced (K0.47Na0.545)(Nb0.55Ta0.45)O3 (KNNT) powder. In the Lee et al KNNT study, the introduction of A-site non-stoichiometry (excess Na ion) was found to affect the MPB, which led to a rise in d33 [11].…”

Section: Introductionmentioning

confidence: 97%

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Ferroelectric KNNT Fibers by Thermoplastic Extrusion Process: Microstructure and Electromechanical Characterization

et al. 2015

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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. OPEN ACCESSActuators 2015, 4 100

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%