Multi-phase coexistence in yttrium-substituted Ba0.9Ca0.1Zr0.07Ti0.93O3 lead-free piezoceramics
| Autor: | K. Chandramani Singh, Shreya Mittal, Radhapiyari Laishram |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
010302 applied physics
Electromechanical coupling coefficient Materials science Process Chemistry and Technology Solid-state reaction route Analytical chemistry chemistry.chemical_element 02 engineering and technology Yttrium Dielectric 021001 nanoscience & nanotechnology 01 natural sciences Ferroelectricity Surfaces Coatings and Films Electronic Optical and Magnetic Materials chemistry visual_art 0103 physical sciences Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Curie temperature Ceramic Crystallite 0210 nano-technology |
| Zdroj: | Ceramics International. 45:1237-1245 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2018.09.312 |
| Popis: | Lead-free Ba0.9Ca0.1Zr0.07Ti0.93O3 + xY2O3(x = 0, 0.02, 0.04, 0.06, 0.08, 0.10) ceramics were prepared following conventional solid state reaction route. The average grain size of the ceramics diminishes with the addition of an appreciable amount of Y3+. All the prepared samples show frequency dispersion at lower temperatures and are relaxors. The ceramic composition with x = 0.02 was found to lie at the multi-phase coexistence region at room temperature, comprising of orthorhombic and tetragonal phases. The Curie temperature (Tc) of this sample is 82 °C, a significant 10 °C rise from that of the undoped sample. The dielectric constant at room temperature (ert), dielectric constant at Curie temperature (em), remnant polarization (Pr) and coercive field (Ec) were also found to be optimum for this particular composition, with ert = 2400, em = 4340, Pr = 6.75 μC/cm2, Ec = 4.21 kV/cm. The piezoelectric charge coefficient (d33) and electromechanical coupling coefficient (kp) were found to be optimized for the ceramics with x = 0.02 mol% yttrium, poled around curie temperature with the values d33 = 204 pC/N and kp = 30%. The study reveals that an optimum amount of Y3+ in Ba0.9Ca0.1Zr0.07Ti0.93O3 can lead to high density with low porosity, large crystallite size and the multi-phase coexistence thereby enhancing the dielectric, ferroelectric and piezoelectric properties of the ceramics. |
| Databáze: | OpenAIRE |
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