40 research outputs found

    Cultural representations in foreign language textbooks: A comparative analysis of English and French language textbooks designed for Algerian state middle schools.

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    This research is the first comparative analysis of the cultural representations (including images of culture, society, and the world) in the recently published English and French language textbooks used in Algerian state middle schools. This qualitative research employs content analysis and Critical discourse analysis informed by Risager’s (2018) theoretical framework to question the cultural representations of four language textbooks (two English and two French language textbooks). In addition to textbook analysis, supplementary data was collected from few policy documents and semi-structured interviews with a sample of teachers to provide an in-depth and triangulated understanding of the philosophy surrounding cultural representation in Algerian foreign language education. The findings show that the English and French language textbooks have similarities and differences in their approach to cultural representation. Both English and French language textbooks’ cultural representations are dominated by essentialist, nationalist, and simplistic representational discourses. The English language textbooks have an emphasis on representing cultural knowledge about different countries (including English speaking countries), but the French language textbooks have no focus on representing countries. The findings reveal that the sociocultural content of the textbooks is predominantly Algerian-centred, and both language textbooks prioritise the development of national identity and pride. Algerian national history is represented in both English and French language textbooks via narratives of anti-colonial resistance, but the French textbooks have more emphasis on representing a negative image of France. As a former French colony, Algeria adopts a political approach to the representation of history and France in the French language textbooks. The findings of the textbook analysis are consistent with the guidelines of the Algerian education policy documents which heavily promote national identity and history. The interviewed foreign language teachers do not feel the need to question or challenge the nationalist orientation of the cultural representations of the language textbooks

    Comportement thermique et rhéologique d'un verre de silice obtenu par la méthode sol gel

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    85 p. : ill. ; 30 cmLe procédé sol-gel est une nouvelle technique de synthÚse de matériaux vitreux et céramiques. Elle est basé sur deux réactions : l'hydrolyse et la condensation d'un comosé organométallique, le produit obtenu est un gel imprégné de solvant, ce dernier est séché dans des conditions hypercritiques. La transformation de l'aérogel en verre se fait par un simple frittag

    Nouveaux chemins d'accÚs à des molécules-aimants multifonctionnelles par post-fonctionnalisation

    No full text
    Virtual storage spaces (Cloud) has become common today. However, these are not dematerialized and are hosted in data centers (Data Center), they are bulky and energy consuming. Research in the field of magnetic information storage has made considerable progress with, among others, the discovery of single-molecule magnets (SMMs). These compounds could significantly increase the storage capacities of future hard drives. Magnet molecules are complexes of coordination chemistry or organometallic chemistry, isolated from each other. They have intrinsic magnetic properties unlike conventional magnets where the magnetic information retention properties come from a cooperative effect of all molecules in the material. This therefore results in a noticeable difference in the capacity for storing information. The first magnet-molecule, the famous [Mn12], was discovered in 1980. Its magnetic properties were characterized a few years later, thus opening a new chapter in the field of molecular magnetism. The characteristics of a molecule-magnet are linked to the energy barrier that defines these complexes: ΔE = | D | SÂČ (D for anisotropy and S for the spin of the complex). From 2003, the replacement of transition metals by lanthanide ions revolutionized research in this field. Previous laboratory work has shown that the nuclearity of molecular structures and the number of ligands have a major impact on the magnetic properties of the molecule-magnet. It turns out that the simplest complexes are generally those with the best performance. The main subject of the thesis is to develop mononuclear complexes. The idea is to be able to subsequently modify these compounds by post-functionalization of the organic ligand in order to exacerbate the magnetic performances and / or to add new properties (luminescence for example, multifunctionality) to the initial molecule-magnet. To do this, a library of original ÎČ-diketone ligands was produced. These ligands have functions which subsequently make it possible to carry out organic modification reactions on the magnet molecule. Two post-functionalization reactions were thus considered: a Palladium-coupling reaction (Sonogashira or Suzuki-Miyaura) and a click reaction (Huisgen cycloaddition). A second aim of this thesis is based on the results of a recent theoretical study which proposes the use of the sulfur atom in the coordination sphere of the metal center of the SMM. The latter would improve the axiality of the molecule and therefore the magnetic properties of the final molecular structure. The synthesis of sulfur analogues of ÎČ-diketone ligands was then undertaken to study the influence of the sulfur atom compared to its oxygenated counterparts in the final magnet molecule. ÎČ-monothioketone and keto-sulfoxide ligands have therefore been synthesized. The corresponding lanthanide ion-based complexes have been isolated, their molecular structures as well as their magnetic and luminescence properties have been characterized.L’utilisation d’espaces de stockage virtuels (Cloud) est devenue courante aujourd’hui. NĂ©anmoins ces derniers ne sont pas dĂ©matĂ©rialisĂ©s et sont hĂ©bergĂ©s dans des centres de donnĂ©es (Data Center), ils sont encombrants et Ă©nergivores. La recherche dans le domaine du stockage de l’information magnĂ©tique a connu des avancĂ©es considĂ©rables avec, entre autres, la dĂ©couverte des molĂ©cules-aimants (SMM, Single-Molecule Magnets, en anglais). Ces composĂ©s pourraient augmenter considĂ©rablement les capacitĂ©s de stockage des prochains disques durs. Les molĂ©cules-aimants sont des complexes de chimie de coordination ou de chimie organomĂ©talliques, isolĂ©s les uns des autres. Elles possĂšdent des propriĂ©tĂ©s magnĂ©tiques intrinsĂšques contrairement aux aimants classiques oĂč les propriĂ©tĂ©s de conservation de l’information magnĂ©tique proviennent d’un effet coopĂ©ratif de toutes les molĂ©cules du matĂ©riau. Il en rĂ©sulte donc une diffĂ©rence notable dans la capacitĂ© de stockage de l’information. La premiĂšre molĂ©cule-aimant, le cĂ©lĂšbre [Mn12], est dĂ©couverte en 1980. Ses propriĂ©tĂ©s magnĂ©tiques sont caractĂ©risĂ©es quelques annĂ©es plus tard ouvrant ainsi un nouveau chapitre dans le domaine du magnĂ©tisme molĂ©culaire. Les caractĂ©ristiques d’une molĂ©cule-aimant sont liĂ©s Ă  la barriĂšre d’énergie qui dĂ©finit ces complexes : ΔE = |D|SÂČ (D pour l’anisotropie et S le spin du complexe). A partir de 2003, le remplacement des mĂ©taux de transition par les ions lanthanide a rĂ©volutionnĂ© les recherches dans ce domaine. De mĂȘme, les travaux antĂ©rieurs du laboratoire ont permis de dĂ©montrer que la nuclĂ©aritĂ© des Ă©difices molĂ©culaires et le nombre de ligands avaient une grande incidence sur les propriĂ©tĂ©s magnĂ©tiques de la molĂ©cule-aimant. Il en ressort que les complexes les plus simples sont gĂ©nĂ©ralement ceux qui prĂ©sentent les meilleures performances. Le sujet principal de la thĂšse consiste Ă  Ă©laborer des complexes mononuclĂ©aires. L’idĂ©e est de pouvoir par la suite modifier ces composĂ©s par post-fonctionnalisation du ligand organique dans le but d’exacerber les performances magnĂ©tiques et/ou d’additionner de nouvelles propriĂ©tĂ©s (luminescence par exemple, multifonctionnalitĂ©) Ă  la molĂ©cule-aimant initiale. Pour ce faire, une bibliothĂšque de ligands de type ÎČ-dicĂ©tone originaux a Ă©tĂ© rĂ©alisĂ©e. Ces ligands possĂšdent des fonctions qui permettent par la suite de rĂ©aliser des rĂ©actions de modifications organiques sur la molĂ©cule-aimant. Deux rĂ©actions de post-fonctionnalisations ont ainsi Ă©tĂ© envisagĂ©es : un couplage au palladium (Sonogashira ou Suzuki-Miyaura) et une rĂ©action click (cycloaddition de Huisgen). Un second objectif de cette thĂšse basĂ© sur les rĂ©sultats d’une Ă©tude thĂ©orique rĂ©cente qui propose l’emploi d’atome de soufre dans la sphĂšre de coordination du centre mĂ©tallique de la molĂ©cule-aimant. Ce dernier amĂ©liorerait l’axialitĂ© de la molĂ©cule et donc les propriĂ©tĂ©s magnĂ©tiques de l’édifice molĂ©culaire final. La synthĂšse d’analogues soufrĂ©s de ligands de types ÎČ-dicĂ©tone a alors Ă©tĂ© entreprise afin d’étudier l’influence de l’atome de soufre comparĂ©e Ă  ses homologues oxygĂ©nĂ©s au sein de la molĂ©cule-aimant finale. Des ligands ÎČ-monothiocĂ©tone et sulfoxyde ont donc Ă©tĂ© synthĂ©tisĂ©s. Les complexes correspondant Ă  base d’ions lanthanide ont Ă©tĂ© isolĂ©s, leurs structures molĂ©culaires ainsi que leurs propriĂ©tĂ©s magnĂ©tiques et de luminescences ont Ă©tĂ© caractĂ©risĂ©es

    New access to multifunctionnal single-molecule magnets via post-modification routes

    No full text
    L’utilisation d’espaces de stockage virtuels (Cloud) est devenue courante aujourd’hui. NĂ©anmoins ces derniers ne sont pas dĂ©matĂ©rialisĂ©s et sont hĂ©bergĂ©s dans des centres de donnĂ©es (Data Center), ils sont encombrants et Ă©nergivores. La recherche dans le domaine du stockage de l’information magnĂ©tique a connu des avancĂ©es considĂ©rables avec, entre autres, la dĂ©couverte des molĂ©cules-aimants (SMM, Single-Molecule Magnets, en anglais). Ces composĂ©s pourraient augmenter considĂ©rablement les capacitĂ©s de stockage des prochains disques durs. Les molĂ©cules-aimants sont des complexes de chimie de coordination ou de chimie organomĂ©talliques, isolĂ©s les uns des autres. Elles possĂšdent des propriĂ©tĂ©s magnĂ©tiques intrinsĂšques contrairement aux aimants classiques oĂč les propriĂ©tĂ©s de conservation de l’information magnĂ©tique proviennent d’un effet coopĂ©ratif de toutes les molĂ©cules du matĂ©riau. Il en rĂ©sulte donc une diffĂ©rence notable dans la capacitĂ© de stockage de l’information. La premiĂšre molĂ©cule-aimant, le cĂ©lĂšbre [Mn12], est dĂ©couverte en 1980. Ses propriĂ©tĂ©s magnĂ©tiques sont caractĂ©risĂ©es quelques annĂ©es plus tard ouvrant ainsi un nouveau chapitre dans le domaine du magnĂ©tisme molĂ©culaire. Les caractĂ©ristiques d’une molĂ©cule-aimant sont liĂ©s Ă  la barriĂšre d’énergie qui dĂ©finit ces complexes : ΔE = |D|SÂČ (D pour l’anisotropie et S le spin du complexe). A partir de 2003, le remplacement des mĂ©taux de transition par les ions lanthanide a rĂ©volutionnĂ© les recherches dans ce domaine. De mĂȘme, les travaux antĂ©rieurs du laboratoire ont permis de dĂ©montrer que la nuclĂ©aritĂ© des Ă©difices molĂ©culaires et le nombre de ligands avaient une grande incidence sur les propriĂ©tĂ©s magnĂ©tiques de la molĂ©cule-aimant. Il en ressort que les complexes les plus simples sont gĂ©nĂ©ralement ceux qui prĂ©sentent les meilleures performances. Le sujet principal de la thĂšse consiste Ă  Ă©laborer des complexes mononuclĂ©aires. L’idĂ©e est de pouvoir par la suite modifier ces composĂ©s par post-fonctionnalisation du ligand organique dans le but d’exacerber les performances magnĂ©tiques et/ou d’additionner de nouvelles propriĂ©tĂ©s (luminescence par exemple, multifonctionnalitĂ©) Ă  la molĂ©cule-aimant initiale. Pour ce faire, une bibliothĂšque de ligands de type ÎČ-dicĂ©tone originaux a Ă©tĂ© rĂ©alisĂ©e. Ces ligands possĂšdent des fonctions qui permettent par la suite de rĂ©aliser des rĂ©actions de modifications organiques sur la molĂ©cule-aimant. Deux rĂ©actions de post-fonctionnalisations ont ainsi Ă©tĂ© envisagĂ©es : un couplage au palladium (Sonogashira ou Suzuki-Miyaura) et une rĂ©action click (cycloaddition de Huisgen). Un second objectif de cette thĂšse basĂ© sur les rĂ©sultats d’une Ă©tude thĂ©orique rĂ©cente qui propose l’emploi d’atome de soufre dans la sphĂšre de coordination du centre mĂ©tallique de la molĂ©cule-aimant. Ce dernier amĂ©liorerait l’axialitĂ© de la molĂ©cule et donc les propriĂ©tĂ©s magnĂ©tiques de l’édifice molĂ©culaire final. La synthĂšse d’analogues soufrĂ©s de ligands de types ÎČ-dicĂ©tone a alors Ă©tĂ© entreprise afin d’étudier l’influence de l’atome de soufre comparĂ©e Ă  ses homologues oxygĂ©nĂ©s au sein de la molĂ©cule-aimant finale. Des ligands ÎČ-monothiocĂ©tone et sulfoxyde ont donc Ă©tĂ© synthĂ©tisĂ©s. Les complexes correspondant Ă  base d’ions lanthanide ont Ă©tĂ© isolĂ©s, leurs structures molĂ©culaires ainsi que leurs propriĂ©tĂ©s magnĂ©tiques et de luminescences ont Ă©tĂ© caractĂ©risĂ©es.Virtual storage spaces (Cloud) has become common today. However, these are not dematerialized and are hosted in data centers (Data Center), they are bulky and energy consuming. Research in the field of magnetic information storage has made considerable progress with, among others, the discovery of single-molecule magnets (SMMs). These compounds could significantly increase the storage capacities of future hard drives. Magnet molecules are complexes of coordination chemistry or organometallic chemistry, isolated from each other. They have intrinsic magnetic properties unlike conventional magnets where the magnetic information retention properties come from a cooperative effect of all molecules in the material. This therefore results in a noticeable difference in the capacity for storing information. The first magnet-molecule, the famous [Mn12], was discovered in 1980. Its magnetic properties were characterized a few years later, thus opening a new chapter in the field of molecular magnetism. The characteristics of a molecule-magnet are linked to the energy barrier that defines these complexes: ΔE = | D | SÂČ (D for anisotropy and S for the spin of the complex). From 2003, the replacement of transition metals by lanthanide ions revolutionized research in this field. Previous laboratory work has shown that the nuclearity of molecular structures and the number of ligands have a major impact on the magnetic properties of the molecule-magnet. It turns out that the simplest complexes are generally those with the best performance. The main subject of the thesis is to develop mononuclear complexes. The idea is to be able to subsequently modify these compounds by post-functionalization of the organic ligand in order to exacerbate the magnetic performances and / or to add new properties (luminescence for example, multifunctionality) to the initial molecule-magnet. To do this, a library of original ÎČ-diketone ligands was produced. These ligands have functions which subsequently make it possible to carry out organic modification reactions on the magnet molecule. Two post-functionalization reactions were thus considered: a Palladium-coupling reaction (Sonogashira or Suzuki-Miyaura) and a click reaction (Huisgen cycloaddition). A second aim of this thesis is based on the results of a recent theoretical study which proposes the use of the sulfur atom in the coordination sphere of the metal center of the SMM. The latter would improve the axiality of the molecule and therefore the magnetic properties of the final molecular structure. The synthesis of sulfur analogues of ÎČ-diketone ligands was then undertaken to study the influence of the sulfur atom compared to its oxygenated counterparts in the final magnet molecule. ÎČ-monothioketone and keto-sulfoxide ligands have therefore been synthesized. The corresponding lanthanide ion-based complexes have been isolated, their molecular structures as well as their magnetic and luminescence properties have been characterized

    Nouveaux chemins d'accÚs à des molécules-aimants multifonctionnelles par post-fonctionnalisation

    No full text
    Virtual storage spaces (Cloud) has become common today. However, these are not dematerialized and are hosted in data centers (Data Center), they are bulky and energy consuming. Research in the field of magnetic information storage has made considerable progress with, among others, the discovery of single-molecule magnets (SMMs). These compounds could significantly increase the storage capacities of future hard drives. Magnet molecules are complexes of coordination chemistry or organometallic chemistry, isolated from each other. They have intrinsic magnetic properties unlike conventional magnets where the magnetic information retention properties come from a cooperative effect of all molecules in the material. This therefore results in a noticeable difference in the capacity for storing information. The first magnet-molecule, the famous [Mn12], was discovered in 1980. Its magnetic properties were characterized a few years later, thus opening a new chapter in the field of molecular magnetism. The characteristics of a molecule-magnet are linked to the energy barrier that defines these complexes: ΔE = | D | SÂČ (D for anisotropy and S for the spin of the complex). From 2003, the replacement of transition metals by lanthanide ions revolutionized research in this field. Previous laboratory work has shown that the nuclearity of molecular structures and the number of ligands have a major impact on the magnetic properties of the molecule-magnet. It turns out that the simplest complexes are generally those with the best performance. The main subject of the thesis is to develop mononuclear complexes. The idea is to be able to subsequently modify these compounds by post-functionalization of the organic ligand in order to exacerbate the magnetic performances and / or to add new properties (luminescence for example, multifunctionality) to the initial molecule-magnet. To do this, a library of original ÎČ-diketone ligands was produced. These ligands have functions which subsequently make it possible to carry out organic modification reactions on the magnet molecule. Two post-functionalization reactions were thus considered: a Palladium-coupling reaction (Sonogashira or Suzuki-Miyaura) and a click reaction (Huisgen cycloaddition). A second aim of this thesis is based on the results of a recent theoretical study which proposes the use of the sulfur atom in the coordination sphere of the metal center of the SMM. The latter would improve the axiality of the molecule and therefore the magnetic properties of the final molecular structure. The synthesis of sulfur analogues of ÎČ-diketone ligands was then undertaken to study the influence of the sulfur atom compared to its oxygenated counterparts in the final magnet molecule. ÎČ-monothioketone and keto-sulfoxide ligands have therefore been synthesized. The corresponding lanthanide ion-based complexes have been isolated, their molecular structures as well as their magnetic and luminescence properties have been characterized.L’utilisation d’espaces de stockage virtuels (Cloud) est devenue courante aujourd’hui. NĂ©anmoins ces derniers ne sont pas dĂ©matĂ©rialisĂ©s et sont hĂ©bergĂ©s dans des centres de donnĂ©es (Data Center), ils sont encombrants et Ă©nergivores. La recherche dans le domaine du stockage de l’information magnĂ©tique a connu des avancĂ©es considĂ©rables avec, entre autres, la dĂ©couverte des molĂ©cules-aimants (SMM, Single-Molecule Magnets, en anglais). Ces composĂ©s pourraient augmenter considĂ©rablement les capacitĂ©s de stockage des prochains disques durs. Les molĂ©cules-aimants sont des complexes de chimie de coordination ou de chimie organomĂ©talliques, isolĂ©s les uns des autres. Elles possĂšdent des propriĂ©tĂ©s magnĂ©tiques intrinsĂšques contrairement aux aimants classiques oĂč les propriĂ©tĂ©s de conservation de l’information magnĂ©tique proviennent d’un effet coopĂ©ratif de toutes les molĂ©cules du matĂ©riau. Il en rĂ©sulte donc une diffĂ©rence notable dans la capacitĂ© de stockage de l’information. La premiĂšre molĂ©cule-aimant, le cĂ©lĂšbre [Mn12], est dĂ©couverte en 1980. Ses propriĂ©tĂ©s magnĂ©tiques sont caractĂ©risĂ©es quelques annĂ©es plus tard ouvrant ainsi un nouveau chapitre dans le domaine du magnĂ©tisme molĂ©culaire. Les caractĂ©ristiques d’une molĂ©cule-aimant sont liĂ©s Ă  la barriĂšre d’énergie qui dĂ©finit ces complexes : ΔE = |D|SÂČ (D pour l’anisotropie et S le spin du complexe). A partir de 2003, le remplacement des mĂ©taux de transition par les ions lanthanide a rĂ©volutionnĂ© les recherches dans ce domaine. De mĂȘme, les travaux antĂ©rieurs du laboratoire ont permis de dĂ©montrer que la nuclĂ©aritĂ© des Ă©difices molĂ©culaires et le nombre de ligands avaient une grande incidence sur les propriĂ©tĂ©s magnĂ©tiques de la molĂ©cule-aimant. Il en ressort que les complexes les plus simples sont gĂ©nĂ©ralement ceux qui prĂ©sentent les meilleures performances. Le sujet principal de la thĂšse consiste Ă  Ă©laborer des complexes mononuclĂ©aires. L’idĂ©e est de pouvoir par la suite modifier ces composĂ©s par post-fonctionnalisation du ligand organique dans le but d’exacerber les performances magnĂ©tiques et/ou d’additionner de nouvelles propriĂ©tĂ©s (luminescence par exemple, multifonctionnalitĂ©) Ă  la molĂ©cule-aimant initiale. Pour ce faire, une bibliothĂšque de ligands de type ÎČ-dicĂ©tone originaux a Ă©tĂ© rĂ©alisĂ©e. Ces ligands possĂšdent des fonctions qui permettent par la suite de rĂ©aliser des rĂ©actions de modifications organiques sur la molĂ©cule-aimant. Deux rĂ©actions de post-fonctionnalisations ont ainsi Ă©tĂ© envisagĂ©es : un couplage au palladium (Sonogashira ou Suzuki-Miyaura) et une rĂ©action click (cycloaddition de Huisgen). Un second objectif de cette thĂšse basĂ© sur les rĂ©sultats d’une Ă©tude thĂ©orique rĂ©cente qui propose l’emploi d’atome de soufre dans la sphĂšre de coordination du centre mĂ©tallique de la molĂ©cule-aimant. Ce dernier amĂ©liorerait l’axialitĂ© de la molĂ©cule et donc les propriĂ©tĂ©s magnĂ©tiques de l’édifice molĂ©culaire final. La synthĂšse d’analogues soufrĂ©s de ligands de types ÎČ-dicĂ©tone a alors Ă©tĂ© entreprise afin d’étudier l’influence de l’atome de soufre comparĂ©e Ă  ses homologues oxygĂ©nĂ©s au sein de la molĂ©cule-aimant finale. Des ligands ÎČ-monothiocĂ©tone et sulfoxyde ont donc Ă©tĂ© synthĂ©tisĂ©s. Les complexes correspondant Ă  base d’ions lanthanide ont Ă©tĂ© isolĂ©s, leurs structures molĂ©culaires ainsi que leurs propriĂ©tĂ©s magnĂ©tiques et de luminescences ont Ă©tĂ© caractĂ©risĂ©es

    Effect of the substrate on the structural and electrical properties of dc sputtered Ni thin films

    No full text
    We have studied the effect of the substrate on the structural and electrical properties of Ni thin films. Series of Ni thin films have been prepared by dc diode sputtering on four different substrates, glass, Si(111), Si(100) and mica; the Ni thickness ranges from about 47 nm to 317 nm. We observed that Ni grown on glass has no texture. On the other hand Ni deposited on Si gets the 〈111âŒȘ preferred orientation for all samples, even the thinner ones. Grain sizes were found to increase with increasing thickness for Ni/glass and Ni/Si(100), with the grains in Ni/Si(100) much larger than the corresponding ones for Ni on glass. The lattice constant of Ni on glass is smaller than that of the bulk. For the Ni on Si, however, the lattice constant is practically equal to the bulk value. We noted that the resistivity ρ decreases with increasing thickness and with increasing grain size for practically all samples. Also the Ni thin films deposited on a semiconductor substrate (Si(100) and Si(111)) get a higher resistivity than Ni on an insulator (Ni/glass for example) for the same Ni thickness. No magnetoresistance was observed in these Ni thin films at ambient temperature and for about a half kOe perpendicular magnetic field. These experimental results will be interpreted and discussed

    Effect of thickness on the physical properties of ITO thin films

    No full text
    We have studied the effect of thickness on the structural, optical and electrical properties of In2O3:Sn (ITO) thin films. Two series of ITO thin films have been deposited onto glass substrates by DC sputtering at two partial pressures of oxygen (ppo): 4 × 10−4 and 4.75 × 10−4 mbar. Each series consists of samples with thickness ranging from 306 nm to 1440 nm. We observed a change of texture with thickness; the thinner films grow with a 〈111âŒȘ preferred orientation; however as the thickness increased, the preferred orientation becomes in the 〈100âŒȘ direction. The lattice constant and the grain size have also been obtained from the X-ray spectra. The energy gap, Eg, has been obtained from the transmission curve; Eg is found to decrease with increasing thickness for both series. The electrical resistivity ρ has been studied as a function of thickness, ppo and temperature (T). The temperature was varied from room temperature (RT) to 450 °C and back to RT; a hysteresis effect was observed in the ρ vs. T curve. Also, a minimum in ρ was observed, in all these samples, in the temperature range 260 to 280 °C. For these temperatures, we have studied the effect of annealing time on the electrical resistivity for samples having both textures. We noted that ρ increased with annealing time and reaches a saturation value equal to the RT temperature value. Hall effect experiments were done on all these samples. The concentration n and the mobility ÎŒH were obtained. These parameters are found to be sensitive to the thickness and the texture of these films. All these results will be correlated and discussed
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