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2nd Edition of International Conference on

Materials Science and Engineering

March 28 -30, 2022 | Singapore

2021 Speakers

Size-dependent properties in BaTiO3- based ceramics

Lavinia-Petronela Curecheriu, Speaker at
Alexandru Ioan Cuza University from Iasi, Romania
Title : Size-dependent properties in BaTiO3- based ceramics

Abstract:

Due to the continuous trend of miniaturization in microelectronics industry, the interest concerning scale dependent phenomena in ferroelectric materials attracted a broad interest in the last years. Apart the need to understand how to preserve the functional properties comparative to ones of bulk material when reducing the size down to nanoscale, there is also a specific interest concerning the maximization of dielectric, piezoelectric and ferroelectric properties at some specific grain size. Concerning this aspect, the researchers dedicated mainly to the critical grain size (GS) of BaTiO3 around 1 μm, for which enhanced dielectric, ferroelectric and piezoelectric properties have been always found, irrespective of the synthesis procedure and sintering method [1,2]. However, systematic studies to find a similar critical GS in other BaTiO3-based compounds have not been previously performed. 
In this work, a series of dense BaTiO3-based ceramics (Ba0.85Ca0.15Ti0.90Zr0.10O3 and 5%Zr-BaTiO3) with grain size larger than 1μm and uniform grain-size distribution were successfully prepared by the conventional solid-state reaction, and the grain-size effects on the structural, dielectric, ferroelectric and piezoelectric properties were explored in their un-poled and poled states. The ceramics were obtained by sintering solid state powders at different temperatures between 1200-1500°C and times (from 0.2-24 hours). The grain size of ceramics determined from SEM images were between 1 μm for the samples sintered at lower temperature and  ~140 μm for higher sintering temperature. The structural characterization was performed for monitoring the effect of grain size and field on the phase composition in BaTiO3-based ceramics. The evolution of polar order and phase transitions with grain size has been studied using dielectric permittivity measurements at 20Hz- 2MHz between 25 and 150°C. Also, the piezoelectric properties at different poling conditions (poling temperature and electric field) were investigated and discussed according with ceramics grain size. Polarization vs. electric field (P-E) hysteresis loop study showed that exist a critical grain size (~ 9 μm) for which the remnant and saturation polarisation is higher. In addition, we develop a mesoscale modelling (Monte Carlo with Finite Element Method calculations) to describe size effects on the low-field properties in  BaTiO3-based ceramics. The presented data provide a complete picture of the size effect dependence of functional properties in BaTiO3-based ceramics.

Biography:

Lavinia Curecheriu is Lecteur at Departament of Physics from the “Alexandru Ioan Cuza” University of Iasi, Romania. She graduated in Biophysics at the “Alexandru Ioan Cuza” University of Iasi, Romania in 2004. Afterwards, she completed the Ph.D in Physics in 2010 at the same university. She has 12 years of experience in investigating by a combined experimental and theoretical approach fundamental phenomena in multifunctional oxides with polar order (ferroelectrics and multiferroics) in relationship with their composition and micro/nanostructure. She has published 60 articles in ISI peer-reviewed journals. For her research activity, she was awarded with: Award "IUVENTAS SCIENTIAES" given by UAIC for young researcher for 2014-2015; Young researcher in Science and Engineering in 2015, and  “L’ORÉAL-UNESCO Romania for Women and Science Award 2017”. 

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