Premium
Crystal Phase Control of Luminescing α‐NaGdF 4 :Eu 3+ and β‐NaGdF 4 :Eu 3+ Nanocrystals
Author(s) -
Ptacek P.,
Schäfer H.,
Kömpe K.,
Haase M.
Publication year - 2007
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.200600974
Subject(s) - materials science , phase (matter) , stoichiometry , nanocrystal , ion , hexagonal phase , crystal (programming language) , crystal structure , fluoride , ethylenediamine , impurity , metal ions in aqueous solution , metal , nanomaterials , luminescence , analytical chemistry (journal) , crystallography , inorganic chemistry , chemistry , nanotechnology , organic chemistry , computer science , metallurgy , programming language , optoelectronics , chromatography
NaGdF 4 :Eu 3+ , NaEuF 4 , and NaGdF 4 nanocrystals were synthesized in the high‐boiling coordinating solvent N ‐(2‐hydroxyethyl)‐ethylenediamine (HEEDA). Phase pure nanomaterials, crystallizing either in the cubic α‐phase or the hexagonal β‐phase, were obtained by adjusting one reaction parameter only, i.e., the molar ratio between metal and fluoride ions in the synthesis. The hexagonal β‐phase is formed, if this molar ratio is close to stoichiometric, whereas the cubic α‐phase is obtained in the presence of excess metal ions. The optical properties of the Eu 3+ doped samples are different for the two crystal phases. The results indicate an increased number of oxygen impurities close to Eu 3+ ions, if excess metal ions are used in the synthesis.