Tesis sobre el tema "Supraconducteur haute température critique"
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Roblin-Semène, Laurence. "Composites "verre-supraconducteur à haute température critique"". Montpellier 2, 1994. http://www.theses.fr/1994MON20099.
Texto completoTALL, PAPA DOUTA. "Etude du supraconducteur à haute température critique YBa2Cu3O7-x : dislocations et plasticité". Poitiers, 1992. http://www.theses.fr/1992POIT2312.
Texto completoFissette, Simon. "Fabrication d'un bolomètre supraconducteur à haute température critique opérant dans les micro-ondes". Mémoire, Université de Sherbrooke, 2009. http://savoirs.usherbrooke.ca/handle/11143/4818.
Texto completoGrison, Xavier. "Etude d'un supraconducteur à haute température critique par effet Josephson et spectroscopie tunnel". Palaiseau, Ecole polytechnique, 2000. http://www.theses.fr/2000EPXX0037.
Texto completoOuanani, Saphia. "Étude de réseaux de jonctions Josephson à haute température critique". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS208.
Texto completoThe Josephson junction (JJ) is the basis of many compound superconducting electronic circuits (SQUID detectors millimeter wave RSFQ logic). With the discovery of HTS superconductors (high critical temperature), intensive research has been undertaken to make JJ operating at the temperature of liquid nitrogen (77 K) allowing the use of a compact cryogenics. However, the complexity of these materials has long hampered the development of a viable technology and simple to implement. Among the junctions manufacturing methods, one using the ion beam irradiation has reached a sufficiently high degree of maturity to be able to envisage the production of circuits having thousands of JJ to HTS.The aim of my thesis is based on the fabrication, characterization and study of the electromagnetic properties of Josephson arrays achieved in thin films of YBa2Cu3O7-d. by the ion irradiation method
Elbaa, Mohamed. "Caractérisation et modélisation des matériaux supraconducteurs à haute température critique". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0196.
Texto completoThe aim of this thesis is to optimize the process of magnetization of superconducting pellets at high critical temperature (SHTC) by pulsed field magnetization (PFM) in order to use them in applications in the field of electrical engineering. In the design phase of the inductor necessary to magnetize these SHTC pellets, modeling and simulation are strongly recommended to perform the necessary calculations of the various electrical characteristics of the magnetization system. Therefore, we have developed an analytical model to study the influence of the presence of a superconducting bulk on the value of the inductance of an induction coil in a ferromagnetic circuit. The aim is to solve the Laplace and Poisson equations in different regions of interest through the magnetic vector potential. The analytical resolution was performed (carried out) using a computer code developed under MATLAB where the results obtained were in good agreement with those obtained by numerical simulation under COMSOL. The inhomogeneity of YBaCuO type SHTC pellets in terms of critical current density Jc was also investigated. To do this, we carried out experiments on the magnetization of these bulks by the PFM method. We have shown that the flat surface containing the crystallization germ (seed) of these pellets is characterized by a higher Jc than the other surface. Also, we studied the influence of the position of the seed crystallization in the two-pellet characterization method
Fauqué, Benoît. "Etude des supraconducteurs à haute température critique par diffusion des neutrons". Phd thesis, Université Paris Sud - Paris XI, 2007. http://tel.archives-ouvertes.fr/tel-00349921.
Texto completoHoàng, Thê Cuong. "Caractérisation des supraconducteurs à haute température critique en vue d'application en électrotechnique". Thesis, Nancy 1, 2010. http://www.theses.fr/2010NAN10129/document.
Texto completoThe main of this thesis is the characterization of high critical temperature superconductors (HTS). First, we have presented the generality of the HTS. The possible use in the future, of the HTS for the transport current, involves to study more particularly the losses in self-field, or fed by a sinusoidal current. Then we have recalled the losses calculations based on the Bean model critical state for various forms of the sample, as a plate, a cylinder, a tube cylindrical hollow and an HTS cable. For the second time, we have characterized the HTS which allows make the characteristics E(J), U(I), Jc(B), and n(B) of an HTS tube cylindrical hollow. The characterization has been made by the electrical method. Then we have tried a self-field compensation of an HTS tube by two different methods. After we have measured the magnetic field diffusion in an HTS plate and we have determined its Jc by the magnetic field measurement in complete penetration. In the last time, we have calculated analytically the losses in self-field of the HTS tube, using the Bean model critical state. We have also showed that in self-field, the magnetic field penetration inside the HTS material happens in order. First of all, there is magnetic field incomplete penetration from outside to inside the material, then when the penetration is complete, the magnetic field increase uniformly throughout the material. These losses calculation results have been compared to measurement results, this comparison shows a clear coincidence. For the last experiment, we have measured and analysed the losses in an HTS coils fed by a sinusoidal current 50Hz frequency. These results have showed that the losses of this HTS coils are mainly losses in the superconducting material and not in the superconducting matrix
Farhat, Mohamad. "Contribution à la modélisation 3D du champ électromagnétique dans les supraconducteurs à haute température critique". Thesis, Université de Lorraine, 2019. http://www.theses.fr/2019LORR0083/document.
Texto completoSuperconducting materials have particular physical and geometric properties that require spatial-temporal modeling approaches fines, where conventional methods quickly reach their limits in terms of convergence, precision and computational time. The latter can be very consistent, which is incompatible with the design and optimization problems. In this context, this work aims to develop rapid multiphysics modeling approaches for the design and optimization of superconductor-based systems. Particular attention is paid to the integral methods. Scientific obstacles to overcome, which also constitute the originality of the work lies in the integration of behavior laws E (J) of superconducting digital patterns of such methods. A numerical model is developed for a rapid computation of eddy currents in multifilamentary high temperature superconductive (HTS) for the evaluation of AC losses. The developed model is based on an integro-differential formulation in terms of the electric vector potential in the frequency and temporal domains. A test campaign is conducted to validate and clearly identify the possibilities and limitations of this approach for modeling superconductors
Hoàng, Thê Cuong. "Caractérisation des supraconducteurs à haute température critique en vue d'application en électrotechnique". Electronic Thesis or Diss., Nancy 1, 2010. http://www.theses.fr/2010NAN10129.
Texto completoThe main of this thesis is the characterization of high critical temperature superconductors (HTS). First, we have presented the generality of the HTS. The possible use in the future, of the HTS for the transport current, involves to study more particularly the losses in self-field, or fed by a sinusoidal current. Then we have recalled the losses calculations based on the Bean model critical state for various forms of the sample, as a plate, a cylinder, a tube cylindrical hollow and an HTS cable. For the second time, we have characterized the HTS which allows make the characteristics E(J), U(I), Jc(B), and n(B) of an HTS tube cylindrical hollow. The characterization has been made by the electrical method. Then we have tried a self-field compensation of an HTS tube by two different methods. After we have measured the magnetic field diffusion in an HTS plate and we have determined its Jc by the magnetic field measurement in complete penetration. In the last time, we have calculated analytically the losses in self-field of the HTS tube, using the Bean model critical state. We have also showed that in self-field, the magnetic field penetration inside the HTS material happens in order. First of all, there is magnetic field incomplete penetration from outside to inside the material, then when the penetration is complete, the magnetic field increase uniformly throughout the material. These losses calculation results have been compared to measurement results, this comparison shows a clear coincidence. For the last experiment, we have measured and analysed the losses in an HTS coils fed by a sinusoidal current 50Hz frequency. These results have showed that the losses of this HTS coils are mainly losses in the superconducting material and not in the superconducting matrix
Massat, Pierre. "Spectroscopie Raman du supraconducteur FeSe". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC059/document.
Texto completoThe discovery in 2008 of the iron-based superconductors opened a new field of investigation of high-temperature superconductivity. In particular, the nematic phase of these materials may play a major role in the mecanism of superconductivity. We studied the FeSe compound using Raman spectroscopy, at ambient pressure and under hydrostatic pressure. This material does not display any static magnetic order at ambient pressure and is therefore an excellent choice to study the nematic order. We observed the charge nematic fluctuations. Their evolution in the tetragonal phase proves the existence of an electronic nematic instability, which drives the structural transition. In the orthorhombic phase, the behaviour of the phonons underlines the role of the spin-phonon coupling in the nematic transition. Besides, the shape of the superconducting Raman response is compatible with the existence of two s-wave gaps, one of which is anisotropic. Under hydrostatic pressure, the nematic fluctuations reduce rapidly. The associated electronic quantum critical point is situated at very low pressure, just before the appearance of magnetic order. The nematic fluctuations completely disappear around 2 GPa, when the structural transition changes from second order to first order. An anomaly of the phonons also occurs close to this pressure, which indicates a modification of the electronic structure of the system. Our measurements additionally reveal the existence of a pseudogap. Its temperature of appearance reduces significantly simultaneously to the disappearance of magnetic order, when the critical temperature of superconductivity reaches its maximum. Finally, the Raman response in the superconducting state at 7.8 GPa shows a clear signature of a full gap
Himbele, John. "Contribution à l'étude d'un insert dipolaire supraconducteur à haute température critique pour accélérateur des particules, utilisent le concept de câble multi-rubans torsadé". Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAT108/document.
Texto completoThis Ph.D. deals with a high Tc superconducting (HTS) dipole insert using a twisted stacked cable for a particle accelerator in the framework of EuCARD2 project in CERN. The HTS dipole insert is the only possibility today to go above 16 T for the future high-energy particle accelerator. Two specifications of these HTS insert are large operating currents (> 10 kA) and high background fields (> 13 T) leading to severe operating conditions. To meet these expectations, a first Twisted Stacked/ Block-type HTS insert is proposed based on analytical, numerical and experimental approaches. The works are mainly classified into dipole insert design and twisted stacked cable design. This Ph.D. ends with the best solution for Twisted Stacked/ Block-type HTS insert using partially-insulated cable
Jaudet, Cyril. "Effet de Haas-van Alphen dans les supraconducteurs à haute température critique". Toulouse 3, 2009. http://thesesups.ups-tlse.fr/701/.
Texto completoThis thesis work is based on quantum oscillation measurements of the magnetization in high temperature superconductors. These materials were discovered in 1986 by Bednorz and Müller. They are characterized by the presence of CuO2 planes of which the electronic concentration can be changed. At low doping, these systems have insulating behavior, the electron being localised by strong Coulomb repulsion. At very high doping, these systems recover Fermi liquid behavior. Between these two extremes there is a superconducting dome at which the maximum critical temperature corresponding to a doping, called optimum, arises. Various experimental probes reveal, on the underdoped side, the presence of the so-called \emph{pseudogap} phase. The physics of this system raise several fundamental questions: What is the nature of this \emph{pseudogap} phase and what is the pairing mechanism at the origin of this superconductivity. During this thesis, we have developed a measurent system of the magnetization with a piezoresistive cantilever under high magnetic field and at very low temperature. Our measurements have revealed the presence of quantum oscillations of the magnetization for the first time on each side of the phase diagram. These oscillations attest of the existence of a closed and coherent Fermi surface which evolves from a huge orbit of holes on the overdoped side to a Fermi surface containing one or several small pockets on the underdoped side. Moreover, the presence of a beating in these oscillations suggest the restoration of the coherence along the c-axis at very low temperature and at very high magnetic field on the underdoped side. These different experimental facts are consistent with a Fermi liquid fundamental state. The \emph{pseudogap} is a hallmark of the appearance of an ordered phase in competition with superconductivity
Farhat, Mohamad. "Contribution à la modélisation 3D du champ électromagnétique dans les supraconducteurs à haute température critique". Electronic Thesis or Diss., Université de Lorraine, 2019. http://www.theses.fr/2019LORR0083.
Texto completoSuperconducting materials have particular physical and geometric properties that require spatial-temporal modeling approaches fines, where conventional methods quickly reach their limits in terms of convergence, precision and computational time. The latter can be very consistent, which is incompatible with the design and optimization problems. In this context, this work aims to develop rapid multiphysics modeling approaches for the design and optimization of superconductor-based systems. Particular attention is paid to the integral methods. Scientific obstacles to overcome, which also constitute the originality of the work lies in the integration of behavior laws E (J) of superconducting digital patterns of such methods. A numerical model is developed for a rapid computation of eddy currents in multifilamentary high temperature superconductive (HTS) for the evaluation of AC losses. The developed model is based on an integro-differential formulation in terms of the electric vector potential in the frequency and temporal domains. A test campaign is conducted to validate and clearly identify the possibilities and limitations of this approach for modeling superconductors
Benkel, Tara. "Contribution à la conception et réalisation d’un insert supraconducteur haute température critique pour l’obtention de champ magnétique intense". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAT009/document.
Texto completoRecent improvements in High Temperature Superconductors (HTS) make them promising for large scale applications. They show astonishing properties, especially at very low temperature where they are able to carry high amount of current. These conductors are also built on a nickel alloy substrate allowing them to face severe mechanical stresses. For these reasons, HTS are now placed at the heart of numerous projects for building a next generation of high field magnets. This work is conducted in the NOUGAT project, which intends to design and build a 10 T HTS insert working in a 20 T background field. Despite their outstanding properties, HTS conductors show strong inhomogeneities in their performance along their length. This added to their high heat capacity can be at the origin of local hot spots. The transition to a dissipative state on this local area is then difficult to detect; because of the low speed of its propagation. The transition signal is likely to be lost in the high noise level environment, which can lead the winding to severe or irreversible damages.One way of dealing with this problem is to create coils where the electric insulation is removed and replaced by a metallic layer, the so-called Metal-as-Insulation winding technique. In this configuration and in a case of an inhomogeneity, the current bypasses through the turn-to-turn contact resistance and prevents the winding from burning. However, in such kind of winding field stability and linearity can be an issue. The slower dynamics obtained with this method prevent its use in some applications.The main focus of this work is therefore insulated coils especially the study of the transition behaviour to explore the possibility of reliable protections. In the same extend, the present work also considers safe ways to evaluate the performance of a wound sample in order for it to work with appropriate margins when at nominal operating conditions. This would decrease the need of a strong detection/protection system: the high heat capacity of the conductor makes windings unlikely to be damaged by an outside event.For practical reasons, the NOUGAT project will be built using MI technique, and therefore some MI coils results are presented in this work for comparison purpose. In a first step, the general design constrains for the NOUGAT project insert are defined, especially tape requirements and performance calculations. This underlines the necessity of characterizing the HTS conductor under high field and at low temperature, under conditions similar to the expected operation of the final insert prototype.In a second step, this experimental short sample characterization is implemented in a model to simulate the behaviour of pancake coils designed to build magnet. The aim of the model is to investigate on the transition start and propagation inside the winding. One of the main specificities is the simulation of the whole winding taking as an input the continuous critical current density measurement given by the providers at 77 K, self-field.The last axis of this work is the study of several wound samples allowing comparison between both insulated and metallic insulated windings. Their electric, magnetic, mechanic and thermal behaviours are examined as well as the coupling issues while working inside an outer magnet. Experimental results are compared to preliminary calculations and modelling results. An experimental protocol to safely evaluate coil performance margins is also proposed and tested successfully.Conclusions are then drawn about the possibility to operate safely full scale HTS magnets with present day conductor performances
Bergeal, Nicolas. "Effet Josephson pour l'étude des supraconducteurs à haute température critique". Phd thesis, Université Pierre et Marie Curie - Paris VI, 2005. http://tel.archives-ouvertes.fr/tel-00012161.
Texto completod'un simple film mince d'YBa2Cu3O6+ en combinant des procédés standards de microfabrication et des étapes d'irradiation ionique. D'un point de vue fondamental, nous avons montré que l'effet de proximité joue un rôle important dans le couplage Josephson. Les résultats sont interprétés dans le cadre d'une approche de type quasiclassique basée sur les équations d'Usadel. Du point de vue des applications, ces jonctions offrent une nouvelle technologie efficace pour les dispositifs à base de jonctions Josephson, pouvant fonctionner à la température de l'azote liquide. Sur la base de cette technique, nous avons développé la fabrication de SQUIDs dc ayant de très bonnes performances.
La seconde partie de cette thèse a eté consacrée à l'étude des fluctuations de paires dans le régime de pseudogap des cuprates sous-dopés par une expérience de type Josephson. Si l'on couple un supraconducteur optimalement dopé avec un supraconducteur sous-dopé au travers d'une barrière isolante, la présence de fluctuations de paires dans le régime du pseudogap peut être révélée en mesurant la caractéristique courant-tension pour des températures comprises entre les deux Tc. Pour réaliser cette expérience, nous avons développé une nouvelle technique de fabrication de jonctions à géométrie mesa (YBaCuO sousdopé/PrBaCuO/ YBaCuO optimalement dopé) de taille micronique. Un comportement Josephson a été observé à basse température lorsque les deux électrodes sont dans l'état supraconducteur. Dans le régime intermédiaire, lorsque le composé optimalement dopé est dans l'état supraconducteur et le composé sousdopé dans l'état de pseudogap, nous observons une signature des fluctuations de paires dans un régime de température d'une dizaine de Kelvin au-dessus de la Tc du composé sous-dopé ce qui est bien inférieur à la température d'apparition du pseudogap (250K). Ces résultats sont donc en faveur d'un scénario classique où les fluctuations de paires n'existent qu'au voisinage de la transition.
Douine, Bruno. "Étude des pertes dans les supraconducteurs à haute température critique". Nancy 1, 2001. http://docnum.univ-lorraine.fr/public/SCD_T_2001_0180_DOUINE.pdf.
Texto completoThe objective of this of thesis is the theoretical and experimental loss study in the high critical temperature superconductors (HTS). The specific characteristics of the SHTC led us to reflect on the validity of the formulas of self field losses deduced from Bean model, for a sinusoidal and non sinusoidal current. We sought to know the distribution of current and the losses in the tube. Using the numerical results of losses, and dimensional analysis, we obtained a new relation giving the losses in incomplete penetration. In the experimental part, we observe that the losses do not depend on the current shape, if Imax<1,3*IC. If Imax>1,3*IC the shape of the current intervenes on the value of the losses. In the last part, we compared measurements with calculations of losses, in sinusoidal mode. We checked that the losses measured and calculated with this distribution of current, are rather close
Girard, Antoine. "Nouveaux substrats métalliques à texture biaxiale pour câbles supraconducteurs à haute température critique". Phd thesis, Chambéry, 2006. http://tel.archives-ouvertes.fr/tel-00118093.
Texto completoDes essais sur des laminoirs différents, avec ou sans lubrification et en modifiant le taux d'écrouissage ont permis de mettre en évidence des effets de peau et d'optimiser le procédé de déformation.
Les températures de recuit ont été choisies à la suite de caractérisations de texture avant et après le recuit ainsi que de mesures in-situ par diffraction de rayons X durs durant la montée en température.
Des laminages supérieurs à 98% et des recuits entre 900°C et 950°C en atmosphère protectrice ont permis d'obtenir des rubans ayant une forte texture cubique : désorientations hors du plan (DT) de 5° et dans le plan de 8°. Une partie de la surface est cependant maclée (entre 8% et 10%). Celle-ci entraîne localement de fortes désorientations.
L'état de surface a été contrôlé et amélioré par l'utilisation de rouleaux polis miroirs, l'optimisation des conditions de recuit (atmosphère et durée du palier) ainsi que l'ajout d'une étape d'électropolissage.
Des essais mécaniques et magnétiques ainsi qu'une étude d'oxydation ont été pratiqués pour vérifier le comportement du ruban dans les conditions d'utilisation comme dans les conditions rencontrées pendant les différents étapes de la réalisation du câble.
Le dépôt d'une couche d'oxyde protectrice LZO, sur le substrat a été réalisé avec succès. Les conditions d'un prétraitement sous atmosphère sulfurée, nécessaire à une bonne épitaxie de la couche, ont été déterminées : 1 h à 600°C avec un flux à 0,2 ppm d'H2S.
Enfin des essais sur le développement d'un alliage à barrière de diffusion in situ Cu Ni Y permettant de s'affranchir de la première couche tampon ont été menés.
Bergeal, Nicolas. "Effet Josephson pour l' étude des supraconducteurs à haute température critique". Paris 6, 2005. http://www.theses.fr/2005PA066477.
Texto completoDelerue, Johann. "Matrices de bolomètres supraconducteurs à haute température critique pour l'infrarouge : matériaux, technologies et caractérisations optiques". Paris 6, 2002. http://www.theses.fr/2002PA066098.
Texto completoFrachet, Mehdi. "Etudes ultrasonores de l'état normal des cuprates supraconducteurs à haute température critique". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAY063.
Texto completoIn cuprates, copper oxides, an unconventionnal superconductivity appears by chemical doping between a Mott insulator and a correlated Fermi liquid. Beyond superconductivity, the phase diagram includes multiple broken symmetry phases, including spin and charge density waves. All these phases interact together and with superconductivity, in a complex way. A deeper knowledge of this phase diagram is without doubt a necessary step toward the resolution of the high-Tc enigma. In this aim, we propose in this experimental thesis to measure velocity and attenuation of sound in the low temperature normal state of cuprates, using high magnetic fields.The first (main) part of this thesis focus on the magnetism of La2-xSrxCuO4 (LSCO). In this compound, an antiferromagnetic glass competes with superconductivity. By applying high magnetic fields of the order of 90 T we show that, when superconductivity is weakened enough, the antiferromagnetic glass disappears together with the pseudogap. The persistence of this order up to p*, and the associated ordered magnetic moment, could explain recent observations at p* without necessarily implying that the pseudogap is an ordered phase. Among them are the fall of the Hall number and quantum criticality signatures observed in different cuprates.The shorter second part deals with a related topic: the two distinct charge density waves (CDW, 2D and 3D) of YBa2Cu3O6+_ (Y-123). By performing sound velocity measurements in high magnetic fields we constrain the doping range of the 3D CDW and show that the latter is unlikely at the origin of the Fermi surface reconstruction. Sound velocity measurements also allow the determination of dTc/dεi, the Tc's susceptibility to a given elastic deformation. The complex and anisotropic doping dependence of dTc/dεi cannot be easily reconcile alone with a scenario of competition between CDW(s) and superconductivity
Stemmann, Guntram. "Etude des excitations de spin dans les supraconducteurs à haute température critique". Grenoble 1, 1994. http://www.theses.fr/1994GRE10017.
Texto completoGuibadj, Abdenacer. "Réalisation de multicouches pour supraconducteurs à haute température critique par méthode chimique". Grenoble 1, 2009. http://www.theses.fr/2009GRE10135.
Texto completoStudy and development by MOD of the buffer layers Ce02 and La2Zr207 (LZO) for coated conductors. Various precursors of Cerium was studied, the spin coating was used to make the deposits. The TGA of the various precursors (Ce(EH)3, Cee acac )3, Ce(prop)3 et LZ(ProP)7) allowed the determination of their decomposition mode (loss of mass), to determine their tempe rature of crystallization and to discuss the mixed nature of LZ(ProP)7. The microstructure and the texture of the films of Ce02 and LZO are studied by DRX. AFM and MEB was used to study roughness, the topology and the morphology of the surfaces. The heat treatment of the buffer layers Ce(EH)3/STO and LZ(prop )7/LAO under various atmospheres enabled us to differentiate the polycrystalline growth from the epitaxial growth. The in-situ control of the P02 at during the stage of crystallization makes it possible to improve the texture of the buffer layers. The rate of increasing temperature has an influence on the nucleation that was studied. Finally, one carried out multi-Iayer Ce02/LZO/LAO and YBaCuO/Ce02/YSZ/IBAD which is superconducting
Lecrevisse, Thibaud. "Contribution à l'Etude des aimants supraconducteurs utilisant des matériaux supraconducteurs à haute température de transition". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00904070.
Texto completoBalédent, Victor. "Paramètre d'ordre magnétique dans la phase de pseudogap des oxydes de cuivre supraconducteurs à haute température critique". Phd thesis, Université Paris Sud - Paris XI, 2010. http://tel.archives-ouvertes.fr/tel-00683440.
Texto completoLeckel, Olivier. "Structures accommodant la non-stoechiométrie dans l'oxyde supraconducteur Tl2Ba2CuO6±x à haute température critique : corrélation avec les propriétés supraconductrices". Lyon 1, 1995. http://www.theses.fr/1995LYO10149.
Texto completoPailhès, Stéphane. "Etude des excitations magnétiques dans le supraconducteur à haute température critique Y1-xCaxBa2Cu3O7-delta par diffusion inélastique des neutrons". Paris 6, 2004. http://www.theses.fr/2004PA066483.
Texto completoFlechet, Bernard. "Interconnexions en matériaux supraconducteur (haute température critique) et conducteur normal : performances comparées pour les applications en électronique rapide refroidie". Grenoble INPG, 1991. http://www.theses.fr/1991INPG0018.
Texto completoUlysse, Christian. "Bolomètres à électrons chauds à supraconducteurs haute température critique pour les ondes submillimétriques : élaboration et caractérisations". Paris 6, 2003. http://www.theses.fr/2003PA066327.
Texto completoLadret, Daniel y Béatrice Cabon. "Étude de dispositifs passifs microondes en technologie supraconductrice à haute température critique". Grenoble INPG, 1995. http://www.theses.fr/1995INPG0014.
Texto completoBourges, Philippe. "DYNAMIQUE DE SPINS DANS LES OXYDES DE CUIVRE SUPRACONDUCTEURS A HAUTE TEMPÉRATURE CRITIQUE". Habilitation à diriger des recherches, Université Paris Sud - Paris XI, 2003. http://tel.archives-ouvertes.fr/tel-00003467.
Texto completoFleiter, Jérôme. "Étude de l'implémentation de supraconducteurs à haute température critique dans les aimants d'accélérateur". Phd thesis, Université de Grenoble, 2013. http://tel.archives-ouvertes.fr/tel-00911430.
Texto completoHusse, Emmanuelle. "Conception, réalisation et caractérisation de composants passifs microondes supraconducteurs à haute température critique". Lille 1, 1996. http://www.theses.fr/1996LIL10184.
Texto completoMangin-Thro, Lucile. "Ordre magnétique à q=0 dans les cuprates supraconducteurs à haute température critique". Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLS170/document.
Texto completoThis work is motivated by the study of the intra-unit-cell magnetic order in cuprate high temperature superconductors. It has been already reported in four cuprate families by using polarized neutron scattering, and it is well documented in a wide hole doping range. This order develops below Tmag, which matches the pseudo-gap temperature T*. This magnetic phase could be induced by the staggered orbital magnetism within the unit cell as proposed in the loop current model. This intra-unit-cell magnetic order indicates that time reversal symmetry is broken, but translation invariance is preserved. Experimentally, the goal is not only to systematically verify the existence of this intra-unit-cell magnetic order, but also to seize its nature. We particularly focused on two bilayer systems, YBa2Cu3O6+x and Bi2Sr2CaCu2O8+x. First, we revealed the persistence of the intra-unit-cell magnetic order at relatively high Tmag, near optimal doping. Compared to samples with a lower hole doping level, the magnetic intensity is strongly reduced. We demonstrated that this is due to finite magnetic correlation lengths. Moreover, we determined the associated magnetic structure factor along c, which displays a unique sharp decreasing. It is consistent with a model in which the sum of two anapoles within the bilayer is pointing along b*. Besides, below Tmag, we confirmed the existence of a tilt of the magnetic moment. However, we showed that at high temperature an Ising-like response along the c-axis is recovered. Finally, we proved that the magnetic signal associated to the intra-unit-cell magnetic order is still increasing in the superconducting state
Badoux, Sven. "Propriétés de l'état normal des cuprates sous-dopés sous champ magnétique intense". Toulouse 3, 2014. http://thesesups.ups-tlse.fr/2625/.
Texto completoIn this thesis, we have studied in high temperature superconductors and their phase diagram. Since their discovery in 1986, these materials have generated great interest, especially because of their high critical temperature. In the generic phase diagram of these materials, the superconducting phase is a dome with a maximal critical temperature, which defines the under-doped side (left-side of the phase diagram) and the over-doped side (right-side of the phase diagram). The dome is located between an insulating phase and a metallic phase (Fermi-liquid like). In order to understand the origin of superconductivity, it is essential to characterize the normal phase from which superconductivity arises, in particular at low temperature. Therefore, high magnetic fields were needed to destroy superconductivity and restore the low temperature normal state. Quantum oscillations have been discovered in 2007 in these materials, thanks to resistivity and magnetization measurements under high magnetic fields and low temperature. Quantum oscillations and negative Hall and Seebeck coefficients have revealed the presence of a small electron pocket in the Fermi surface of the underdoped side, covering only 2% of the first Brillouin zone (FBZ). This is in disagreement with band-structure calculations. In contrast quantum oscillations in overdoped cuprates revealed the large hole-like orbit, covering 65% of the FBZ, as predicted by the band structure calculations. The presence of this small electron pocket in underdoped compounds can be explained by a Fermi surface reconstruction. Indeed, RMN and X-rays measurements have shown the presence of a charge density wave in competition with superconductivity. To study the relationship between the Fermi surface deduced from quantum oscillations and the charge order, we have followed the evolution of the oscillation frequencies as a function of doping. Therefore, we have performed different measurements on YBa2Cu3Oy in a wide range of doping, magnetic fields (up to 70T) and temperatures. We also used hydrostatic pressure to induce a change of doping on the same sample. These measurements have revealed the presence of a new series of oscillations with a lower frequency which has been associated to a holepocket. This result allows us to explain some of the transport properties measured in YBa2Cu3Oy compound. In addition, we have also performed transport measurements in HgBa2CuO4+? samples, considered as a textbook material of the cuprate family (monolayer structure and no CuO chain). We have succeeded to observe quantum oscillations similar to those observed in YBa2Cu3Oy. This demonstrates the universality of this phenomenon in cuprates and clearly demonstrates that reconstruction of the Fermi surface involves the quintessential CuO2 planes. Finally, we have performed various simulations of Fermi surface reconstruction based on a biaxial charge order recently discovered by NMR, X-ray and sound velocity measurements. The reconstructed Fermi surface has been compared with experimental measurements
Pugnat, Pierre. "Etude de l'irréversibilité et de l'anisotropie du vecteur aimantation des supraconducteurs à haute température critique". Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10049.
Texto completoJulien, Marc-Henri. "Des supraconducteurs à haute température critique aux échelles de spins : une étude par résonance magnétique nucléaire". Université Joseph Fourier (Grenoble ; 1971-2015), 1997. http://www.theses.fr/1997GRE10283.
Texto completoGillet, Jean-Alain. "Etude par résonance magnétique nucléaire des oxydes supraconducteurs à haute température critique YBa2Cu3O(6+x)". Université Joseph Fourier (Grenoble), 1994. http://www.theses.fr/1994GRE10113.
Texto completoDes, Ligneris Benoît. "Étude des pertes CA dans un ruban supraconducteur à haute température critique à l'aide de la méthode calorimétrique par annulation". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape9/PQDD_0016/MQ56892.pdf.
Texto completoSmina, Abdellatef. "Contribution a l'étude des mécanismes de dissipation dans les supraconducteurs à haute température critique". Tours, 1996. http://www.theses.fr/1996TOUR4007.
Texto completoLecrevisse, Thibault. "Contribution à l'étude des aimants supraconducteurs utilisant des matériaux supraconducteurs à haute température de transition". Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00875176.
Texto completoKermorvant, Julien. "Dissipation par effet Joule en régime hyperfréquence dans les supraconducteurs à haute température critique". Phd thesis, Ecole Polytechnique X, 2010. http://tel.archives-ouvertes.fr/tel-00604160.
Texto completoRichard, Laurence. "Défauts, plasticité et propriétés physiques induites des supraconducteurs à haute température critique : YBa2Cu3O7-x". Poitiers, 1997. http://www.theses.fr/1997POIT2265.
Texto completoPourtier-Marty, Florence. "Étude et réalisation de jonctions tunnel et Josephson à partir d'oxydes supraconducteurs à haute température critique". Grenoble INPG, 1994. http://www.theses.fr/1994INPG0092.
Texto completoYan, Yong. "Non-stoechiométrie et défauts structuraux dans les supraconducteurs de type "123" à haute température critique". Lyon 1, 1992. http://www.theses.fr/1992LYO10303.
Texto completoKazakov, Serguei. "A la recherche de nouveaux supraconducteurs à haute température critique dans le système Sr-K-Bi-O". Université Joseph Fourier (Grenoble), 1998. http://www.theses.fr/1998GRE10169.
Texto completoDe, Almeida-Didry Sonia. "Synthèse de la phase sous-dopée du système supraconducteur à haute température critique Bi2 Sr2CaCu2O8+s et étude par diffusion des neutrons". Thesis, Tours, 2010. http://www.theses.fr/2010TOUR4043/document.
Texto completoWarsito. "Etude magnéto-optique à effet Faraday du comportement de dispositifs supraconducteurs à haute température critique". Caen, 2003. http://www.theses.fr/2003CAEN2023.
Texto completoEyidi, Dominique. "Microstructures d'oxydes supraconducteurs à haute température critique à base de mercure ; modification par déformation plastique". Poitiers, 1999. http://www.theses.fr/1999POIT2317.
Texto completoIngold, Michèle. "Synthèse, études microstructurale et texturale d'oxydes supraconducteurs à haute température critique Y-Ba-Cu-O". Grenoble 1, 1990. http://www.theses.fr/1990GRE10139.
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