On the coloration properties of CaF2 : Na
نویسندگان
چکیده
2014 We have investigated the dichroic properties and the existence of metastable excited states of several colour centres created by X-irradiation in CaF2 : Na. According to our results absorption bands peaking at 600, 385 and 322 nm are associated to the same centre which behaves optically as orthorhombic. The lack of observation of a metastable state is in favour of the F+2A model for this centre. On the other hand the band at 500 nm and another absorption at 322 nm are proved to belong to the same centre which behaves optically as tetragonal. A metastable excited state of this centre with lifetime of 0,83 s at 77 K has been detected. Two possible models are discussed for this centre. J. Physique Lett. 46 (1985) L-861 L-868 15 SEPTEMBRE 1985, Classification Physics Abstracts 61.70D 78.50
منابع مشابه
Study structural and up-conversion luminescence properties of polyvinyl alcohol/CaF2:erbium nanofibers for potential medical applications
Objective(s): This paper describes synthesisPolyvinyl Alcohol/CaF2:Er nanofibers because of its photoluminescence properties.Materials and Methods: First, CaF2:Er nanocomposite synthesized with co-precipitation method. In order to prepare polyvinyl alcohol (PVA)/CaF2:Er nanofibers, CaF2:Er nanocomposites were added to the polyvinyl alcohol (PVA) polymer. PVA/CaF2:Er composite nanofibers were...
متن کاملThe Crystallization Effect on the Optical Properties of Oxyfluoride Glass-Ceramics Containing CaF2 Nanocrystals Doped with Y3+ Ions
In the present study, the oxyfluoride glasses of SiO2-Al2O3-CaF2 system containing different amounts of Y3+ ions were prepared through the convenient melting method. The crystallization temperatures and size of the CaF2 nanocrystals were obtained from DTA curves and XRD patterns, respectively. As a consequence, the optimum amount...
متن کاملLuminescence Properties of Oxyfluoride Glass and Glass Ceramic Doped with Y3 + Ions
Oxyfluoride glass ceramics containing CaF2nano-crystals doped with Y3+ ions were prepared by one-step crystallization of SiO2- Al2O3- CaO- CaF2 glasses at different temperatures. X- ray diffraction (XRD) results have revealed that CaF2 was the only precipitated crystalline phase in glass ceramic samples. According to the XRD results, a glass ceramic was selected as the best sample in order to ...
متن کاملThe Effect of CaF2 Content in Hot Metal Pretreatment Flux Based on Lime
This research was conducted for the purpose of studying the effect of CaF2 content in the composition of hot metal pretreatment flux, based on lime. It was followed in regards to the importance of fluorine amount decrease in hot metal pretreatment and steel making processes. For this purpose, lime based fluxes including 40, 30, 20 and 10 percent calcium fluoride were prepared and hot metal pret...
متن کاملThe effects of Na & Mg adsorption on the electrical properties of SiCNTs: A DFT study
In the present study we focused on the electronic and structural properties of Na and Mg adsorption on the surface of the (6, 6) armchair SiCNTs. The adsorption energy (Eads), band gap energy (Eg), partial density of state (PDOS), chemical potential (μ), global hardness (η), electrophilicity index (ω), global softness (S), work function values (φ) and work function change (Δφ) are calculated by...
متن کامل