Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was invest...Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid shift.These two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.展开更多
Tungsten (W), with its primary advantages, is considered as the most promising candidate for plasma facing materials (PFMs) for the next generation of fusion devices such as ITER. However, continuous bombardment with ...Tungsten (W), with its primary advantages, is considered as the most promising candidate for plasma facing materials (PFMs) for the next generation of fusion devices such as ITER. However, continuous bombardment with 14.1 MeV neutron introduces Frenkel defects as the primary damage in W [1]. The Frenkel defects, composed of self-interstitial atoms (SIAs) and vacancies, can develop to extended defects such as voids and interstitial clusters, resulting in hardening, swelling and embrittlement of W, thus degrading the properties of W [2]. The recombination of SIAs and vacancies is an effective way to reduce the Frenkel defects in bulk W, which enhances the radiation resistance of W based on recent theoretical calculations [3,4]. The moving of the SIA to the vacancy could finish the recombination process through instantaneous or thermally activated way [3]. The instantaneous recombination region is an ellipse with the semi-minor axis of 5.4 ? and semi-major axis of 18 ? according to the molecular dynamics calculation [4].展开更多
基金Project supported by the National Basic Research Program of China(2014CB643801)
文摘Y3Al5O12:Ce3+ is the most famous phosphor material due to its excellent photolumincent properties.Here,through first-principles calculation,the effect of carbon interstitial defects on Y3Al5O12:Ce3+phosphor was investigated. It is found that the carbon interstitials tend to occupy the next-nearest sites of Ce3+ion in Y3Al5O12:Ce3+ lattice. Specially,these interstitial defects can shorten the Ce3+-O2-bond length, leading to a larger crystal field splitting of 5 d orbital of the Ce3+atom and bigger 5 d centroid shift.These two factors cause the emission spectrum of Y3Al5O12(C):Ce3+red shift compared with that of Y3Al5O12:Ce3+. Moreover, with our comparison experiment, we find that the Y3Al5O12(C):Ce3+ has an obvious red shift compared with that of Y3Al5O12:Ce3+system,which is in accord with our first principles calculation. Our work systematically investigates the impact of the carbon interstitial defect on Y3Al5O12:Ce3+,and provides a new route to tune the emission spectrum in Y3Al5O12:Ce3+.
基金supported by the National Magnetic Confinement Fusion Program (Grant No. 2013GB109002)the National Natural Science Foundation of China (Grant Nos. 11405006, and 51371019)
文摘Tungsten (W), with its primary advantages, is considered as the most promising candidate for plasma facing materials (PFMs) for the next generation of fusion devices such as ITER. However, continuous bombardment with 14.1 MeV neutron introduces Frenkel defects as the primary damage in W [1]. The Frenkel defects, composed of self-interstitial atoms (SIAs) and vacancies, can develop to extended defects such as voids and interstitial clusters, resulting in hardening, swelling and embrittlement of W, thus degrading the properties of W [2]. The recombination of SIAs and vacancies is an effective way to reduce the Frenkel defects in bulk W, which enhances the radiation resistance of W based on recent theoretical calculations [3,4]. The moving of the SIA to the vacancy could finish the recombination process through instantaneous or thermally activated way [3]. The instantaneous recombination region is an ellipse with the semi-minor axis of 5.4 ? and semi-major axis of 18 ? according to the molecular dynamics calculation [4].
