Browsing by Author "Capoen, Bruno"

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    Effects of heat treatment and TiO2 content on the optical properties of Eu3+ doped TiO2–SiO2 thin films
    (Elsevier, 2012) Berkani, Oualid; Latrous, Khelil; ElHamzaoui, Hicham; Capoen, Bruno; Bouazaoui, Mohamed
    The photoluminescence properties of Eu3+- doped TiO2–SiO2 thin films were investigated.The films were deposited on silicon substrates by thesol–gel process using the dip-coatingmethod.Themolar ratio ofTiO2 content was varied from25%to100%,while Europium concentration was fixed to1%.The obtained films were calcinatedatvarioustemperaturesrangingfrom400 1C to1300 1C, whichallowed determiningtheoptimalconditionsfortheEu3þ luminescence.Meanwhile,thestructureofTiO2–SiO2 powders,preparedinthesameconditionsasthefilms,wasalsostudiedbyRamanspectroscopy. It revealedtheroleofEuropiumandSiO2 on thestabilizationoftheanatasephaseandtheimportance of thesilicamatrixinthecontroloftitaniaparticlesize
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    Raman Spectroscopic Investigation Of The Effects Of Heat-treatment And Al, Ce Or Eu Doping Concentration On Tio2 Powder Crystallization
    (Oum-El-Bouaghi University, 2016) Berkani, Oualid; El Hamzaoui, Hicham; Latrous, Khelil; Capoen, Bruno; Bouazaoui, Mohamed
    In this paper, we study the effects of various doping elements (Aluminum, Cerium or Europium) with different contents and of heat-treatment on the structural properties of TiO2 nano-crystalline powders. The sol-gel technique was used to prepare the doped and undoped TiO2 powders. The structures of the obtained samples were investigated using Raman spectroscopy, which allowed to monitor the formation of anatase and rutile crystalline phases as a function of the annealing temperature. We have shown that all the doping elements contribute to stabilize anatase phase at high calcination temperature. Furthermore, doping with Europium was found to be the most efficient anatase phase stabilizer.