摘要
In the present work,the transparent oxyfluoride glass-ceramic samples containing GdF3:RE^3+(RE=Tb,Eu)nanocrystals(nGCs)were fabricated via controlled heat-treatment of precursor xerogels prepared using a sol-gel method.The formation of GdF3 nanocrystalline phase from gadolinium(III)trifluoroacetate was verified based on XRD measurements.The average crystal sizes calculated from Scherrer formula were estimated to^10 nm as well as^6 nm for Tb^3+-and Eu^3+-doped samples,respectively.The optical behavior of prepared sol-gel samples was evaluated based on photoluminescence excitation(PLE)and emission spectra(PL)as well as luminescence decay analysis.Obtained samples exhibit the 5D4→7FJ(J=6-3,Tb3+)and the 5D0→7FJ(J=0-4,Eu3+)emission bands recorded within the visible spectral area under excitation at near-UV(393 nm(Eu^3+),351,369,378 nm(Tb^3+))as well as middle-UV illumination(273 nm(Gd3+)).Additionally,based on recorded decay curves,the luminescence lifetimes(τm)for the 5D4(Tb^3+)and the 5D0(Eu3+)excited states were also evaluated.In general,recorded luminescence spectra and double-exponential character of decay curves for nGCs indicate a successful migration of Tb^3+and Eu^3+dopant ions from amorphous silicate framework to lowphonon energy GdF3 nanocrystal phase.
In the present work,the transparent oxyfluoride glass-ceramic samples containing GdF3:RE3+（RE=Tb,Eu） nanocrystals（nGCs） were fabricated via controlled heat-treatment of precursor xerogels prepared using a sol-gel method.The formation of GdF3 nanocrystalline phase from gadolinium（III） trifluoroacetate was verified based on XRD measurements.The average crystal sizes calculated from Scherrer formula were estimated to～10 nm as well as～6 nm for Tb3+-and Eu3+-doped samples,respectively.The optical behavior of prepared sol-gel samples was evaluated based on photoluminescence excitation（PLE） and emission spectra（PL） as well as luminescence decay analysis.Obtained samples exhibit the 5D4→7FJ(J=6-3,Tb3+)and the 5D0→7FJ(J=0-4,Eu3+) emission bands recorded within the visible spectral area under excitation at near-UV(393 nm(Eu3+),351,369,378 nm(Tb3+)) as well as middle-UV illumination(273 nm(Gd3+)).Additionally,based on recorded decay curves,the luminescence lifetimes（τm） for the 5D4（Tb3+） and the 5D0(Eu3+)excited states were also evaluated.In general,recorded luminescence spectra and double-exponential character of decay curves for nGCs indicate a successful migration of Tb3+ and Eu3+ dopant ions from amorphous silicate framework to lowphonon energy GdF3 nanocrystal phase.
基金
Project supported by the National Science Centre(Poland)(2016/23/B/ST8/01965)
