Segregation Engineering in MgO Nanoparticle-Derived Ceramics: The Impact of Calcium and Barium Admixtures on the Microstructure and Light Emission Properties

Thomas Schwab, Korbinian Aicher, Hasan Razouq, Gregor Zickler, Oliver Diwald* (Korrespondierende/r Autor/in)

*Korrespondierende/r Autor/in für diese Arbeit

Publikation: Beitrag in FachzeitschriftArtikelPeer-reviewed

Abstract

Nanostructured segregates of alkaline earth oxides exhibit bright photo-luminescence emission and great potential as components of earth-abundant inorganic phosphors. We evaluated segregation engineering of Ca(2+)- and Ba(2+)-admixtures in sintered MgO nanocube-derived compacts. Compaction and sintering transform the nanoparticle agglomerates into ceramics with residual porosities of Φ = 24−28%. Size mismatch drives admixture segregation into the intergranular region, where they form thin metal oxide films and inclusions decorating grain boundaries and pores. An important trend in the median grain size evolution of the sintered bodies with d(Ca(10 at. %)) = 90 nm < d(Ba(1 at. %)) = 160 nm < d(MgO) = 250 nm ∼ d(Ca(1 at. %)) = 280 nm < d(Ba(10 at. %)) = 870 nm is rationalized by segregation and interface energies, barriers for ion diffusion, admixture concentration, and the increasing surface basicity of the grains during processing. We outline the potential of admixtures on interface engineering in MgO nanocrystal-derived ceramics and demonstrate that in the sintered compacts, the photoluminescence emission originating from the grain surfaces is retained. Interior parts of the ceramic, which are accessible to molecules from the gas phase, contribute with oxygen partial pressure-dependent intensities to light emission.
OriginalspracheEnglisch
Seiten (von - bis)25493-25502
Seitenumfang10
FachzeitschriftACS Applied Materials & Interfaces (ACS Publications)
Jahrgang13
Ausgabenummer21
Frühes Online-Datum19 Mai 2021
DOIs
PublikationsstatusVeröffentlicht - 19 Mai 2021

Bibliographische Notiz

Funding Information:
T.S., K.A., H.R., G.Z., and O.D. gratefully acknowledge support from the Austrian Science Fund FWF for project no. P-28797. TEM measurements were carried out on a JEOL JEM F200 transmission electron microscope, which was funded by Interreg Österreich-Bayern 2014–2020 (project no. AB 29)–“n2m”, nano-to-macro in lightweight materials.

Systematik der Wissenschaftszweige 2012

  • 210 Nanotechnologie
  • 103 Physik, Astronomie
  • 104 Chemie

Schlagwörter

  • nanostructured ceramics
  • intergranular region
  • segregation engineering
  • ion segregation
  • inorganic phosphors
  • grain growth
  • photoemission properties

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