The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser d...The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3＋/Er^3＋ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3＋/Er^3＋ is also studied, The luminescence intensity increases with the ratio of Yb^3＋/Er^3＋ increasing. The ratio of Yb^3＋/Er^3＋ plays a more important role than the concentration of Er^3＋ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3＋/Er^3＋ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers.展开更多
A transparent tellufite glass-ceramic containing nanocrystals based on the composition of 15Li2O-15Nb2O5-7OTeO2-0. 1ErEr2O3-0. 4Yb2O3 （mol%）was prepared by using a two-step heat-treatment. The XRD patterns show that...A transparent tellufite glass-ceramic containing nanocrystals based on the composition of 15Li2O-15Nb2O5-7OTeO2-0. 1ErEr2O3-0. 4Yb2O3 （mol%）was prepared by using a two-step heat-treatment. The XRD patterns show that the composition of crystals in glass-ceramics is possibly Yb6Te5O19.2 or Er6Te5O19.2, and the dimension of crystals is about 55 nm. The Judd-Ofeh parameters, Ωt, （t = 2, 4, 6）, and the spontaneous emission probability of Er^3＋ in glass and glass-ceramics were calculated from optical absorption spectra. The absorption cross section of Er^3 ：^4I15/2→I13/2 and the emission cross section of Er^3 ＋ ：^4I15/2→I13/2 in two samples were also calculated. Raman scattering spectra of glass and glass-ceramic were measured, the fluorescence spectra and the upconversion spectra of Er^3 ＋ ion in glass and glass-ceramic were compared.展开更多
In this study,a series of Er^3+/Yb^3+co-doped Ca-Mg-Si glasses were prepared via the containerless processing.Phase composition and luminescent properties of the prepared materials were investigated through XRD and sp...In this study,a series of Er^3+/Yb^3+co-doped Ca-Mg-Si glasses were prepared via the containerless processing.Phase composition and luminescent properties of the prepared materials were investigated through XRD and spectrometry,and bioactivity,biocompatibility and cytotoxicity were evaluated.The XRD patterns indicated that akermanite(AKT)ceramic powders were completely transformed into the glassy phase(AKT-G,EYA)through the containerless processing,which exhibit upconversion luminescence,and the luminescence intensity increased with the increase of the doping amount of Er^3+ and Yb^3+.High amount of Yb^3+doping and existence of Ca^2+in glasses resulted in more intensive red-light emission.The SEM observation,combined with EDS analysis,and cell culture experiments showed that the as-prepared glasses were nontoxic,biocompatible and bioactive.All these results demonstrated that the containerless processing is a facile method for preparing homogeneous luminescent bioactive glasses.Furthermore,this luminescent Ca-Mg-Si glasses may be used as bone implant materials to study the in vivo distribution of degradation products of bone implants,which may be of great significance for the development and clinical application of new bone grafting materials.展开更多
Transparent glass ceramics were prepared from the phosphosilicate system by melt-quenching devitrification（MQD） method, i.e., nanocrystals spontaneously form during cooling of the melts. Introduction of 2.5 wt.% Yb2...Transparent glass ceramics were prepared from the phosphosilicate system by melt-quenching devitrification（MQD） method, i.e., nanocrystals spontaneously form during cooling of the melts. Introduction of 2.5 wt.% Yb2O3 and 0.5 wt.% Er2O3 into the glass melt induced the change of type and concentration of crystals. The comparison of rheological and thermodynamic properties of both undoped and Yb^3＋/Er^3＋ doped melts showed that addition of Yb^3＋/Er^3＋ oxides caused increase of liquid fragility, and degree of medium-range order. In addition, the thermodynamic barriers for nucleation ΔG＊ as a function of reduced temperature T/Tm were calculated with an assumption of wetting angle θ=90o, Yb^3＋/Er^3＋ doped melt tended to firstly nucleate as compared to undoped melt at small undercooling.展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 60307004） and the Science and Technology Program of Guangzhou, Guangdong province, China （Grant No 2004Z2-D0131）.
文摘The Er^3＋/Yb^3＋ co-doped TeO2-Nb2O5-Li2O glass is prepared by conventional melting method, and its upconversion spectra are measured. The intense green upconversion luminescence upon excitation with a 976 nm laser diode is observed with the naked eyes. The dependence of luminescence intensity on the ratio of Yb^3＋/Er^3＋ is discussed in detail, and the relationship between the ratio of green luminescence intensity to red luminescence intensity and the ratio of Yb^3＋/Er^3＋ is also studied, The luminescence intensity increases with the ratio of Yb^3＋/Er^3＋ increasing. The ratio of Yb^3＋/Er^3＋ plays a more important role than the concentration of Er^3＋ in determining the upconversion luminescence intensity. The ratio of green luminescence intensity to red luminescence intensity reaches a maximum when ratio of Yb^3＋/Er^3＋ is 3. Thus the glass could be one of the potential candidates for LD pumping solid-state lasers.
文摘A transparent tellufite glass-ceramic containing nanocrystals based on the composition of 15Li2O-15Nb2O5-7OTeO2-0. 1ErEr2O3-0. 4Yb2O3 （mol%）was prepared by using a two-step heat-treatment. The XRD patterns show that the composition of crystals in glass-ceramics is possibly Yb6Te5O19.2 or Er6Te5O19.2, and the dimension of crystals is about 55 nm. The Judd-Ofeh parameters, Ωt, （t = 2, 4, 6）, and the spontaneous emission probability of Er^3＋ in glass and glass-ceramics were calculated from optical absorption spectra. The absorption cross section of Er^3 ：^4I15/2→I13/2 and the emission cross section of Er^3 ＋ ：^4I15/2→I13/2 in two samples were also calculated. Raman scattering spectra of glass and glass-ceramic were measured, the fluorescence spectra and the upconversion spectra of Er^3 ＋ ion in glass and glass-ceramic were compared.
文摘In this study,a series of Er^3+/Yb^3+co-doped Ca-Mg-Si glasses were prepared via the containerless processing.Phase composition and luminescent properties of the prepared materials were investigated through XRD and spectrometry,and bioactivity,biocompatibility and cytotoxicity were evaluated.The XRD patterns indicated that akermanite(AKT)ceramic powders were completely transformed into the glassy phase(AKT-G,EYA)through the containerless processing,which exhibit upconversion luminescence,and the luminescence intensity increased with the increase of the doping amount of Er^3+ and Yb^3+.High amount of Yb^3+doping and existence of Ca^2+in glasses resulted in more intensive red-light emission.The SEM observation,combined with EDS analysis,and cell culture experiments showed that the as-prepared glasses were nontoxic,biocompatible and bioactive.All these results demonstrated that the containerless processing is a facile method for preparing homogeneous luminescent bioactive glasses.Furthermore,this luminescent Ca-Mg-Si glasses may be used as bone implant materials to study the in vivo distribution of degradation products of bone implants,which may be of great significance for the development and clinical application of new bone grafting materials.
基金Project supported by the Natural Science Fund of Elite Young Researchers of Shandong Province(2008BS04004)
文摘Transparent glass ceramics were prepared from the phosphosilicate system by melt-quenching devitrification（MQD） method, i.e., nanocrystals spontaneously form during cooling of the melts. Introduction of 2.5 wt.% Yb2O3 and 0.5 wt.% Er2O3 into the glass melt induced the change of type and concentration of crystals. The comparison of rheological and thermodynamic properties of both undoped and Yb^3＋/Er^3＋ doped melts showed that addition of Yb^3＋/Er^3＋ oxides caused increase of liquid fragility, and degree of medium-range order. In addition, the thermodynamic barriers for nucleation ΔG＊ as a function of reduced temperature T/Tm were calculated with an assumption of wetting angle θ=90o, Yb^3＋/Er^3＋ doped melt tended to firstly nucleate as compared to undoped melt at small undercooling.
