Résultat de la recherche
9 résultat(s) recherche sur le tag 'AFM' 
Affiner la recherche Générer le flux rss de la recherche
Partager le résultat de cette recherche Interroger des sources externesContribution à l’étude de couches minces de siliciures formés sur le silicium / Charafeddine Sedrati
Titre : Contribution à l’étude de couches minces de siliciures formés sur le silicium : (Ni,Co)/Si Type de document : texte imprimé Auteurs : Charafeddine Sedrati, Auteur ; A. Bouabellou, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2015 Importance : 147 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Thin films cobalt nickel silicide sheet resistance RBS GIXRD AFM RAMAN.
Couches minces siliciures résistance carrée ????? ????? ?????? ???????? ??????????? ????????? ??????????Index. décimale : 530 Physique Résumé : This work focuses on the study of the formation of silicides by the solid state reaction in the Co/Ni/Si(100) and Ni/Co/Si(100) systems. The samples are obtained by a vacuum thermal evaporation of Co-Ni and Ni-Co bilayers on Si(100) substrates followed by a thermal annealing in air in the temperature range of 300 - 800 °C. The Grazing incidence X rays diffraction (GIXRD), the Rutherford backscattering spectroscopy (RBS), the atomic force microscopy (AFM), the Raman spectroscopy and the measurement of the electric resistivity by using the our-point method are the experimental techniques employed for samples characterization.
The analysis the Co/Ni/Si(100) system annealed at 300°C shows that the nickel reacts
initially with the Si substrate to form the Ni2Si silicide, and the cobalt diffuses to form
the (CoxNi1 -x)2Si phase. Then, the Ni2Si phase transforms to the NiSi monosilicide
which remains stable up to a temperature of 600°C. In addition, Co begins to react with the silicon to form the various phases of cobalt silicide. Beyond the temperature of 500°C, the ternary (CoxNi1 -x)Si2 phase appears. The formation of this ternary phase is confirmed by the shift of the peaks in the Raman spectrum. RBS technique shows that the ternary phase (CoxNi1 -x)Si2 is formed with different concentrations of Ni and Co elements with the thickness varying between 30 and 50 nm. Electrical measurements show that the obtained ternary silicide is more considered than the binary silicides because of its low resistivity and its high thermal stability.
For the Ni/Co/Si(100) system, the analysis allows to observe the formation of different silicides at different temperatures. Indeed, it is clearly confirmed the coexistence of both CoSi and Co2Si phases at 300 °C, the formation of Ni2Si rich nickel silicide at 400 °C followed by the formation of the NiSi, this latter keeps its thermal stability up to 700 °C, and finally the formation of NiSi2 at 800 ° C. The apparition of the ternary (CoxNi1 -x)Si phase takes place at 500°C.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/SED6806.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10059 Contribution à l’étude de couches minces de siliciures formés sur le silicium : (Ni,Co)/Si [texte imprimé] / Charafeddine Sedrati, Auteur ; A. Bouabellou, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2015 . - 147 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Thin films cobalt nickel silicide sheet resistance RBS GIXRD AFM RAMAN.
Couches minces siliciures résistance carrée ????? ????? ?????? ???????? ??????????? ????????? ??????????Index. décimale : 530 Physique Résumé : This work focuses on the study of the formation of silicides by the solid state reaction in the Co/Ni/Si(100) and Ni/Co/Si(100) systems. The samples are obtained by a vacuum thermal evaporation of Co-Ni and Ni-Co bilayers on Si(100) substrates followed by a thermal annealing in air in the temperature range of 300 - 800 °C. The Grazing incidence X rays diffraction (GIXRD), the Rutherford backscattering spectroscopy (RBS), the atomic force microscopy (AFM), the Raman spectroscopy and the measurement of the electric resistivity by using the our-point method are the experimental techniques employed for samples characterization.
The analysis the Co/Ni/Si(100) system annealed at 300°C shows that the nickel reacts
initially with the Si substrate to form the Ni2Si silicide, and the cobalt diffuses to form
the (CoxNi1 -x)2Si phase. Then, the Ni2Si phase transforms to the NiSi monosilicide
which remains stable up to a temperature of 600°C. In addition, Co begins to react with the silicon to form the various phases of cobalt silicide. Beyond the temperature of 500°C, the ternary (CoxNi1 -x)Si2 phase appears. The formation of this ternary phase is confirmed by the shift of the peaks in the Raman spectrum. RBS technique shows that the ternary phase (CoxNi1 -x)Si2 is formed with different concentrations of Ni and Co elements with the thickness varying between 30 and 50 nm. Electrical measurements show that the obtained ternary silicide is more considered than the binary silicides because of its low resistivity and its high thermal stability.
For the Ni/Co/Si(100) system, the analysis allows to observe the formation of different silicides at different temperatures. Indeed, it is clearly confirmed the coexistence of both CoSi and Co2Si phases at 300 °C, the formation of Ni2Si rich nickel silicide at 400 °C followed by the formation of the NiSi, this latter keeps its thermal stability up to 700 °C, and finally the formation of NiSi2 at 800 ° C. The apparition of the ternary (CoxNi1 -x)Si phase takes place at 500°C.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/SED6806.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10059 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité SED/6806 SED/6806 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et caractérisation de nanocomposites hybrides : Oxydes métalliques/polymères Type de document : texte imprimé Auteurs : Bariza Troudi, Auteur ; Ouahiba Halimi, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 121 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Synthèse hydrothermale Nanocomposites Films minces CuO/PS CuO/PVC PbO/PS PbO/PVC DRX FT-IR Raman AFM Absorption UV-Visible photoluminescence Hydrothermal synthesis thin films UV-Visible Absorption ?????? ?????? ????? ????? ???????? ??? ????????- ???? ???????? ?????? Index. décimale : 530 Physique Résumé : Thin films of metal oxides/polymers nanocomposites were deposited on glass substrates by Spin-Coating and Dip-Coating techniques. The nanocomposites were elaborated by inserting, in the matrices of polystyrene (PS) and polyvinyl chloride (PVC) polymers, of nanoparticles of metal oxides such as copper oxide (CuO) and lead oxide (PbO). The nanoparticles of semiconductor CuO and PbO were synthesized beforehand by the hydrothermal method. The xray diffraction characterization of the obtained powders have revealed a monoclinic phase for CuO crystallites and an orthorhombic phase for PbO. The size of the crystallites of the two semiconductors is of a nanometic order. Calcul the of gap energy indicate a shift towards high energies compared to massive crystals. This shift is due to the effect of the quantum confinement induced by the nanometric size of the crystallites of the semiconductors. These nanocrystals are used for the preparation of the nanocomposites of CuO/PS, CuO/PVC, PbO/PS and PbO/PVC by
simple insertion of CuO and PbO nanoparticles in the PS and PVC polymers. The analysis of the elaborated nanocomposites by X-ray diffraction has allowed to notice the incorporation of the CuO and PbO crystallites into the PS and PVC polymers matrixes and analysis by Raman and infrared spectroscopies has confirmed the presence of CuO and PbO crystallites in the PS and PVC matrixes by revealing specific vibration modes to the Cu-O and Pb-O bonds. The surface morphology and topography of thin films of nanocomposites were highlighted with the help of atomic force microscopy (AFM) and have shown homogeneous dispersion of CuO and PbO crystallites and a low surface roughness. the characterization by measurement of the optical absorption in the UV-Visible domain allows to observe the increase in optical absorption which is attributed to CuO and PbO nanocrystallites because PS and PVC are optically transparent in the UV-Visible domain. A shift of the gap energy of the nanocomposites compared with the gap energy of the pure polymers and the massive crystallites of CuO and PbO was observed. This variation in gap energy is the result of the new optical behavior of the prepared nanocomposites.
The optical characterization by the measure of the photoluminescence has shown that the elaborated samples present intense luminescence bands in the visible range, hence the possibility of consider these matrices as optically active media and can be used for the making devices of specific optics properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/TRO7142.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10460 Elaboration et caractérisation de nanocomposites hybrides : Oxydes métalliques/polymères [texte imprimé] / Bariza Troudi, Auteur ; Ouahiba Halimi, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 121 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Synthèse hydrothermale Nanocomposites Films minces CuO/PS CuO/PVC PbO/PS PbO/PVC DRX FT-IR Raman AFM Absorption UV-Visible photoluminescence Hydrothermal synthesis thin films UV-Visible Absorption ?????? ?????? ????? ????? ???????? ??? ????????- ???? ???????? ?????? Index. décimale : 530 Physique Résumé : Thin films of metal oxides/polymers nanocomposites were deposited on glass substrates by Spin-Coating and Dip-Coating techniques. The nanocomposites were elaborated by inserting, in the matrices of polystyrene (PS) and polyvinyl chloride (PVC) polymers, of nanoparticles of metal oxides such as copper oxide (CuO) and lead oxide (PbO). The nanoparticles of semiconductor CuO and PbO were synthesized beforehand by the hydrothermal method. The xray diffraction characterization of the obtained powders have revealed a monoclinic phase for CuO crystallites and an orthorhombic phase for PbO. The size of the crystallites of the two semiconductors is of a nanometic order. Calcul the of gap energy indicate a shift towards high energies compared to massive crystals. This shift is due to the effect of the quantum confinement induced by the nanometric size of the crystallites of the semiconductors. These nanocrystals are used for the preparation of the nanocomposites of CuO/PS, CuO/PVC, PbO/PS and PbO/PVC by
simple insertion of CuO and PbO nanoparticles in the PS and PVC polymers. The analysis of the elaborated nanocomposites by X-ray diffraction has allowed to notice the incorporation of the CuO and PbO crystallites into the PS and PVC polymers matrixes and analysis by Raman and infrared spectroscopies has confirmed the presence of CuO and PbO crystallites in the PS and PVC matrixes by revealing specific vibration modes to the Cu-O and Pb-O bonds. The surface morphology and topography of thin films of nanocomposites were highlighted with the help of atomic force microscopy (AFM) and have shown homogeneous dispersion of CuO and PbO crystallites and a low surface roughness. the characterization by measurement of the optical absorption in the UV-Visible domain allows to observe the increase in optical absorption which is attributed to CuO and PbO nanocrystallites because PS and PVC are optically transparent in the UV-Visible domain. A shift of the gap energy of the nanocomposites compared with the gap energy of the pure polymers and the massive crystallites of CuO and PbO was observed. This variation in gap energy is the result of the new optical behavior of the prepared nanocomposites.
The optical characterization by the measure of the photoluminescence has shown that the elaborated samples present intense luminescence bands in the visible range, hence the possibility of consider these matrices as optically active media and can be used for the making devices of specific optics properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/TRO7142.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10460 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité TRO/7142 TRO/7142 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. Type de document : texte imprimé Auteurs : Ahmed Reda Khantoul, Auteur ; Miloud Seffari, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 108 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Oxyde de zinc Cobalt Couches minces Dip-Coating Sol-Gel DRX MEB AFM Raman UV-Visible photoluminescence Zinc oxide cobalt thin films SEM ????? ????? ?????? ???? ???????? ???????-??????? ????? ???? ?????? ??????? ?????? ?????????? ?????? ???? ????? ?????? ?????? ????? ?????? ??????? ?????? ?????? ??? ?????????-??????? ????? ?????? ?????? Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and cobalt-doped ZnO with different concentrations of cobalt (Co) (0.5, 1, 5 and 10% in weight) thin films in order to improve the structural, morphological, optical and electrical properties of ZnO. The samples were prepared using the Sol-Gel method and deposited on glass substrates by the Dip-coating ""Dipping-Drawing"" technique. Structural haracterization showed the formation of ZnO of hexagonal structure (wurtzite) with a preferential orientation according to plane (002) and made it possible to determine the nanometric size of the crystallites. The SEM and AFM images revealed the nanometric character of our layers. Raman scattering confirmed the results of the XRD, namely the formation of ZnO with an hexagonal structure (wurtzite). UV-visible spectroscopy has shown that our layers have a transparency, in the visible, which varies between 80 and 98%. It has shown also that the gap decreases with the increase in doping. The hotoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects. The codoping of aluminum to cobalt allowed us also to improve the structural and optical properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHA7383.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11033 Elaboration des Couches minces du Semiconducteur ZnO dopées au Cobalt et étude de leurs propriétés structurales, optiques et électriques. [texte imprimé] / Ahmed Reda Khantoul, Auteur ; Miloud Seffari, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 108 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Oxyde de zinc Cobalt Couches minces Dip-Coating Sol-Gel DRX MEB AFM Raman UV-Visible photoluminescence Zinc oxide cobalt thin films SEM ????? ????? ?????? ???? ???????? ???????-??????? ????? ???? ?????? ??????? ?????? ?????????? ?????? ???? ????? ?????? ?????? ????? ?????? ??????? ?????? ?????? ??? ?????????-??????? ????? ?????? ?????? Index. décimale : 530 Physique Résumé : The present work consists in the elaboration and characterization of the undoped and cobalt-doped ZnO with different concentrations of cobalt (Co) (0.5, 1, 5 and 10% in weight) thin films in order to improve the structural, morphological, optical and electrical properties of ZnO. The samples were prepared using the Sol-Gel method and deposited on glass substrates by the Dip-coating ""Dipping-Drawing"" technique. Structural haracterization showed the formation of ZnO of hexagonal structure (wurtzite) with a preferential orientation according to plane (002) and made it possible to determine the nanometric size of the crystallites. The SEM and AFM images revealed the nanometric character of our layers. Raman scattering confirmed the results of the XRD, namely the formation of ZnO with an hexagonal structure (wurtzite). UV-visible spectroscopy has shown that our layers have a transparency, in the visible, which varies between 80 and 98%. It has shown also that the gap decreases with the increase in doping. The hotoluminescence of the films showed ultraviolet (UV) and visible emissions related to defects. The codoping of aluminum to cobalt allowed us also to improve the structural and optical properties.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHA7383.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=11033 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KHA/7383 KHA/7383 Thèse Bibliothèque principale Thèses Disponible
Titre : Elaboration et étude des couches minces d’oxyde d’étain Type de document : texte imprimé Auteurs : Mourad Khechba, Auteur ; Abderaheman Bouabellou, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2018 Importance : 97 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Couche mince SnO2 dopage Sol-Gel DRX AFM Spectroscopie Raman UV-Vis Ellipsométrie spectroscopique (SE) Thin films doping Raman spectroscopy UV-Visible Ellipsometry Spectroscopic ??????? ??????? ????? ??????? ???????-????-???? ???? ?????? ??????? ???? ????? ?????? ??????? ????? ??????? ?????? ??? ????????? ???????? ???????? ???????? Index. décimale : 530 Physique Résumé : This work is devoted to the development of the tin oxide thin films by the sol-gel method. The effect of the annealing temperature, the number of layers and the doping on the structural and optical properties of the films obtained were investigated. The obtained films are characterized by X-ray diffraction (DRX), RAMAN spectroscopy, atomic force microscopy (AFM), UV-Visible spectroscopy and ellipsometry spectroscopic. Raman spectroscopy results show that the SnO2 thin films are crystallizes in rutile phase. A good crystallization is observed after 3 coats. The results of optical characterization show that all the films are transparent (75 to 85% optical transmittance) in the visible and The energy band gap of all the samples lies in the range of 3.63eV– 3.89eV With regard to doping, undoped and doped tin oxide thin films (SnO2:Cd, SnO2:Al) were deposited by Sol Gel Dip Coating method on glass and silicon Si(100) substrates. The DRX shows that all the films deposited on glass substrates have an amorphous structure. On the other hand, the films deposited on Si (100) substrate crystallize in the rutile phase, with a preferential orientation along the axis (310). AFM observations of the surface show that the doping rate affects the roughness. The grain size and the roughness of the samples decrease with the increase of the doping concentration. The SnO2, SnO2:Cd and SnO2:Al thin films are transparent in the visible region and opaque in the ultraviolet region. The band gap, determined from the transmission spectra for the deposited films, also decreases with the increase in the doping rate (from 06 to 10% Cd, and from 04 to 06% Al). In addition, the increase of the cadmium and aluminum doping concentration causes a slight increase in the refractive index.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHE7337.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10987 Elaboration et étude des couches minces d’oxyde d’étain [texte imprimé] / Mourad Khechba, Auteur ; Abderaheman Bouabellou, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2018 . - 97 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Couche mince SnO2 dopage Sol-Gel DRX AFM Spectroscopie Raman UV-Vis Ellipsométrie spectroscopique (SE) Thin films doping Raman spectroscopy UV-Visible Ellipsometry Spectroscopic ??????? ??????? ????? ??????? ???????-????-???? ???? ?????? ??????? ???? ????? ?????? ??????? ????? ??????? ?????? ??? ????????? ???????? ???????? ???????? Index. décimale : 530 Physique Résumé : This work is devoted to the development of the tin oxide thin films by the sol-gel method. The effect of the annealing temperature, the number of layers and the doping on the structural and optical properties of the films obtained were investigated. The obtained films are characterized by X-ray diffraction (DRX), RAMAN spectroscopy, atomic force microscopy (AFM), UV-Visible spectroscopy and ellipsometry spectroscopic. Raman spectroscopy results show that the SnO2 thin films are crystallizes in rutile phase. A good crystallization is observed after 3 coats. The results of optical characterization show that all the films are transparent (75 to 85% optical transmittance) in the visible and The energy band gap of all the samples lies in the range of 3.63eV– 3.89eV With regard to doping, undoped and doped tin oxide thin films (SnO2:Cd, SnO2:Al) were deposited by Sol Gel Dip Coating method on glass and silicon Si(100) substrates. The DRX shows that all the films deposited on glass substrates have an amorphous structure. On the other hand, the films deposited on Si (100) substrate crystallize in the rutile phase, with a preferential orientation along the axis (310). AFM observations of the surface show that the doping rate affects the roughness. The grain size and the roughness of the samples decrease with the increase of the doping concentration. The SnO2, SnO2:Cd and SnO2:Al thin films are transparent in the visible region and opaque in the ultraviolet region. The band gap, determined from the transmission spectra for the deposited films, also decreases with the increase in the doping rate (from 06 to 10% Cd, and from 04 to 06% Al). In addition, the increase of the cadmium and aluminum doping concentration causes a slight increase in the refractive index.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/KHE7337.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10987 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité KHE/7337 KHE/7337 Thèse Bibliothèque principale Thèses Disponible
Titre : Etude de création de centres colorés dans le fluorure de lithium (LiF) irradié par des ions lourds rapides Type de document : texte imprimé Auteurs : Hamdani Benhacine, Auteur ; A. Meftah, Directeur de thèse Editeur : جامعة الإخوة منتوري قسنطينة Année de publication : 2017 Importance : 98 f. Format : 30 cm. Note générale : 2 copies imprimées disponibles
Langues : Français (fre) Catégories : Français - Anglais
PhysiqueTags : Ions lourds rapides Plomb Centres colorés LiF Absorption optique Photoluminescence AFM Swift heavy ions Lead Color centers Optical absorption ?????? ????? ????? LiF ????? F ????? ?????? ???????? ?????? PL A Index. décimale : 530 Physique Résumé : Single crystals of LiF (Lithium Fluoride) were irradiated with ions lead of energy
ranging between 144 and 840 MeV for electronic stopping power varying between 10 and 20
keV/nm and fluences between 109 and 1011 ions/cm2/s at the GANIL (Grand Accélérateurs
d’Ions Lourds, Caen, France). The samples of LiF were analyzed, before and after irradiation,
by three experimental techniques: optical absorption, the photoluminescence and AFM (Atomic
Force Microscopy) and analyzed according to the fluence and the loss of electronic energy. The
results show that the modifications induced by irradiation are dominated by the creation of
simple defects (centers F) and aggregate defects (Fn centers) and that their concentration
increases with energy and fluence. The evolution of centers F according to the fluence made it
possible to determine the radius of traces along the ion trajectories, by using a simple model of
saturated tracks. The values of these radius lie between 9 and 22 nm and vary according to the
electronic loss of energy.
The accumulation of centers F according to the absorptive energy studied by optical
absorption shows that the average concentration of the center F is given mainly by the density
of average energy absorptive with a weak reduction above 1023 eV/cm3. The photoluminescence
made it possible to observe two very intense bands with 545 and 665 nm which correspond to
the emission of centers F3+ and F2 respectively. The analysis by AFM of damage induced on
the surfaces made it possible to deduce the evolution from radius of the tracks according to the
electronic loss of energy. The radius vary between 9 and 16 nm.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BEN7077.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10524 Etude de création de centres colorés dans le fluorure de lithium (LiF) irradié par des ions lourds rapides [texte imprimé] / Hamdani Benhacine, Auteur ; A. Meftah, Directeur de thèse . - [S.l.] : جامعة الإخوة منتوري قسنطينة, 2017 . - 98 f. ; 30 cm.
2 copies imprimées disponibles
Langues : Français (fre)
Catégories : Français - Anglais
PhysiqueTags : Ions lourds rapides Plomb Centres colorés LiF Absorption optique Photoluminescence AFM Swift heavy ions Lead Color centers Optical absorption ?????? ????? ????? LiF ????? F ????? ?????? ???????? ?????? PL A Index. décimale : 530 Physique Résumé : Single crystals of LiF (Lithium Fluoride) were irradiated with ions lead of energy
ranging between 144 and 840 MeV for electronic stopping power varying between 10 and 20
keV/nm and fluences between 109 and 1011 ions/cm2/s at the GANIL (Grand Accélérateurs
d’Ions Lourds, Caen, France). The samples of LiF were analyzed, before and after irradiation,
by three experimental techniques: optical absorption, the photoluminescence and AFM (Atomic
Force Microscopy) and analyzed according to the fluence and the loss of electronic energy. The
results show that the modifications induced by irradiation are dominated by the creation of
simple defects (centers F) and aggregate defects (Fn centers) and that their concentration
increases with energy and fluence. The evolution of centers F according to the fluence made it
possible to determine the radius of traces along the ion trajectories, by using a simple model of
saturated tracks. The values of these radius lie between 9 and 22 nm and vary according to the
electronic loss of energy.
The accumulation of centers F according to the absorptive energy studied by optical
absorption shows that the average concentration of the center F is given mainly by the density
of average energy absorptive with a weak reduction above 1023 eV/cm3. The photoluminescence
made it possible to observe two very intense bands with 545 and 665 nm which correspond to
the emission of centers F3+ and F2 respectively. The analysis by AFM of damage induced on
the surfaces made it possible to deduce the evolution from radius of the tracks according to the
electronic loss of energy. The radius vary between 9 and 16 nm.
Diplôme : Doctorat en sciences En ligne : ../theses/physique/BEN7077.pdf Format de la ressource électronique : Permalink : https://bu.umc.edu.dz/md/index.php?lvl=notice_display&id=10524 Exemplaires (1)
Code-barres Cote Support Localisation Section Disponibilité BEN/7077 BEN/7077 Thèse Bibliothèque principale Thèses Disponible
Permalink
Permalink
Permalink
Permalink
