| Naslov: | Donor doping of K0.5Na0.5NbO3 ceramics with strontium and its implications to grain size, phase composition and crystal structure |
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| Avtorji: | Hreščak, Jitka (Avtor)
Dražić, Goran (Avtor)
Deluca, Marco (Avtor)
Arčon, Iztok (Avtor)
Kodre, Alojz (Avtor)
Dapiaggi, M. (Avtor)
Rojac, Tadej (Avtor)
Malič, Barbara (Avtor)
Benčan, Andreja (Avtor) |
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| Datoteke: |  Manuscript_text.pdf (2,11 MB)
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| Jezik: | Angleški jezik |
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| Vrsta gradiva: | Delo ni kategorizirano (r6) |
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| Tipologija: | 1.01 - Izvirni znanstveni članek |
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| Organizacija: | UNG - Univerza v Novi Gorici |
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| Opis: | In this study, the particular effects of A-site donor doping in a lead-free piezoceramic material K0.5Na0.5NbO3 (KNN) doped with Sr2+, i.e., the crystal-structure change, the secondary-phase formation and the grain-size decrease, were investigated. The already-reported causes of these effects upon doping KNN were critically discussed and a mechanism of the effects’ formation was suggested and experimentally supported with advanced analytical methods. Extended X-ray absorption fine structure (EXAFS) analyses proved that the Sr occupies the perovskite A-sublattice, and locally modifies the KNN monoclinic structure to cubic. With the help of Sr K-edge EXAFS and wavelength-dispersive X-ray spectroscopy, the Sr was found to be homogenously distributed in the KNN perovskite lattice with 0.5, 1 and 2% Sr and no Sr segregation on the nano level was found in any of the studied samples with transmission electron microscopy. Introducing Sr into the A-sublattice, as well as accounting for the charge-compensating A-site vacancies in the starting composition, causes increasing lattice disorder and microstrain, as determined from a Rietveld refinement of the synchrotron X-ray diffraction data. Above 2% Sr the system segregates the A-site vacancies in a secondary phase in order to release the chemical pressure, as revealed by Raman spectroscopy. All these effects result in an increasing number of low-angle grain boundaries that limit the grain growth and finally lead to a significant grain-size decrease. |
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| Ključne besede: | perovskite, potassium sodium niobate, donor doping, cation vacancies |
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| Leto izida: | 2017 |
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| Št. strani: | 10 |
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| Številčenje: | 37 |
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| COBISS_ID: | 4638715  |
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| URN: | URN:SI:UNG:REP:K6AF7WGV |
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| DOI: | 10.1016/j.jeurceramsoc.2016.12.053 |
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| Licenca: | 
To delo je dosegljivo pod licenco Creative Commons Priznanje avtorstva-Nekomercialno-Brez predelav 4.0 Mednarodna |
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| Število ogledov: | 4011 |
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| Število prenosov: | 305 |
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| Metapodatki: |     |
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| Področja: | Gradivo ni uvrščeno v področja. |
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| | | | Skupna ocena: | (0 glasov) |
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| Vaša ocena: | Ocenjevanje je dovoljeno samo prijavljenim uporabnikom. |
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