Effect of particle size and strain on phase stability of (Li{sub 0.06} Na{sub 0.94}) NbO{sub 3}
- Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai-40085 (India)
Alkaline niobates are most suitable and excellent candidates for lead free piezoceramics, as they exhibit morphotropic phase boundary and have ultra-large piezoresponse similar to them. We provide direct experimental evidence of ferroelectric to paraelectric phase transition in (Li{sub 0.06} Na{sub 0.94})NbO{sub 3} with reduction of particle size using a combination of x-ray and neutron powder diffraction techniques at room temperature. Detailed Rietveld analyses of x-ray data show variation of particle sizes from micrometer to nanometer for sintered, calcined, and ball milled powders. The ferroelectric orthorhombic phase for micron sized powder (∼1.17 μm) is found to transform to paraelectric phase by reducing particle size to ∼10.8 nm. The crystal structure of paraelectric phase has been identified with tetragonal symmetry (P4{sub 2}/mmc) and is found to be a post perovskite phase. The low temperature neutron diffraction studies on the powders with different particle sizes reveal that orthorhombic to rhombohedral phase transition gets suppressed with reducing particle size.
- OSTI ID:
- 22273456
- Journal Information:
- Journal of Applied Physics, Vol. 115, Issue 17; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-8979
- Country of Publication:
- United States
- Language:
- English
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