Quasi-seeded growth, phase transformation, and size tuning of multifunctional hexagonal NaLnF4(Ln = Y, Gd, Yb) nanocrystals via in situ cation-exchange reaction

L. W. Yang, Y. Li, Y. C. Li, J. J. Li, Jianhua Hao, J. X. Zhong, P. K. Chu

Research output: Journal article publicationJournal articleAcademic researchpeer-review

18 Citations (Scopus)

Abstract

In situ cation exchange between alkali ions in ternary alkali lanthanide (Ln3+) fluoride on the nanoscale is reported. Experimental results reveal that the differences in the solubility constants and thermodynamic stability of the reactants and products affect the irreversible cation exchange between potassium and sodium, resulting in the phase transformation of cubic KLnF4to hexagonal NaLnF4. The unusual cation-exchange reaction can be used as an efficient tool to produce seed nuclei and control the nucleation and final size of hexagonal NaLnF4nanocrystals (NCs). During the in situ cation exchange between potassium and sodium and corresponding cubic to hexagonal phase transformation, the stable hexagonal NaLnF4particles serving as the seed nuclei play a key role in the final size of the NCs. The in situ cation exchange approach provides not only valuable insights into the growth dynamics of Ln3+doping-induced size tuning and phase transformation in NaYF4and alkaline-earth fluoride NCs, but also a method to prepare high-quality multifunctional NaLnF4NCs with tunable paramagnetism and multi-color upconversion emission.
Original languageEnglish
Pages (from-to)2254-2262
Number of pages9
JournalJournal of Materials Chemistry
Volume22
Issue number5
DOIs
Publication statusPublished - 7 Feb 2012

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Chemistry

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