Size Control of Nearly Monodisperse beta-NaGdF4 Particles Prepared from Small alpha-NaGdF4 Nanocrystals
Autor(en): | Duehnen, Simon Rinkel, Thorben Haase, Markus |
Stichwörter: | Chemistry; Chemistry, Physical; DELIVERY; EMISSION; GROWTH; INFRARED DOWNCONVERSION PHOTOLUMINESCENCE; LAYER; Materials Science; Materials Science, Multidisciplinary; MECHANISM; NAGDF4 NANOPARTICLES; PROBES; ULTRASMALL; UPCONVERTING NANOPARTICLES | Erscheinungsdatum: | 2015 | Herausgeber: | AMER CHEMICAL SOC | Journal: | CHEMISTRY OF MATERIALS | Volumen: | 27 | Ausgabe: | 11 | Startseite: | 4033 | Seitenende: | 4039 | Zusammenfassung: | NaGdF4 nanocrystals of the hexagonal beta-phase can be prepared with very narrow size distribution from small particles of the cubic alpha-phase of NaGdF4, but until now, this method does not allow to control the final particle size. Here we show that the size of beta-NaGdF4 particles can be varied between 4 nm and more than 60 nm by using small alpha-phase particles with different sodium content as precursor. Heating of the 34 nm alpha-phase particles dispersed in oleic acid/octadecene solvent leads to Ostwald-ripening and the formation of beta-NaGdF4 particles with narrow size distribution in all cases. The size of the beta-NaGdF4 particles increases with increasing sodium deficiency of the alpha-phase particles indicating that the number of beta-phase seeds nucleating in the system depends on the ratio of sodium to gadolinium used in the synthesis of the alpha-phase material. |
ISSN: | 08974756 | DOI: | 10.1021/acs.chemmater.5b01013 |
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