KJ Ceramics 31

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Detailed Program

Paper Number : LP-I14

Time Frame : 16:55~17:20

Presentation Date : Friday, 28, November

Session Name : Leadfree Piezoelectrics

Session Chair 1# : Chang Won Ahn

Session Chair 2# : Tonshaku Tou

Regarding electric-field-induced transition between ferroelectric and relaxor

Wook Jo

Ulsan National Institute of Science and Technology

(Bi1/2Na1/2)TiO3 (BNT)-BaTiO3 (BT) solid solution system is one of the most attended lead-free piezoceramic systems over the last decades due to many scientifically intriguing issues such as alleged antiferroelectricity with relaxor features, highly sophisticated temperature-dependent polymorphisms, the presence of morphotropic phase boundary (MPB) similar to that in the market dominating PZT ceramics,, etc. In addition, compositional modifications usually result in the birth of so-called ‘incipient’ piezoelectric strains that are typically about two times as large as those the conventional lead-based piezoceramics can deliver. A key to resolving the existing issues for the system is to identify the phase stability that depends on various thermodynamic variables such as temperature, composition, and electric field. In this talk, we present comprehensive aspects of the phase stability of BNT-BT piezoceramics revealed by temperature-dependent dielectric permittivity measurements, pyroelectric/ferroelectric measurements, as well as in situ diffraction studies. The role of Ba in BNT piezoceramic as well as the intriguing feature of the phase diagram will be discussed in detail.

Acknowledgements :

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