Download or read book Synth se et tude du grenat de fer et d yttrium written by Philippe Grosseau (auteur en génie des procédés).) and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Les pièces polycristallines de grenat de fer et d'yttrium Y3Fe5O12 (YIG) utilisées en hyperfréquences doivent présenter une densité très proche de la valeur théorique. Industriellement, ces pièces sont élaborées par frittage de la poudre qui est préparée par réaction entre les oxydes Y2O3 et Fe2O3. Ce travail concerne l'étude de deux procédés d'élaboration des poudres de YIG qui sont la réaction entre oxydes et la coprécipitation. Dans les deux cas, la formation de la pérovskite de fer et d'yttrium YFeO3 (YIP) précède la formation du grenat. Lors de la synthèse par coprécipitation, la quantité de YIP formée est cependant fortement influencée par la présence d'impuretés ou de dopants (résidus de synthèse, substitution du fer par l'aluminium). L'influence des paramètres d'élaboration sur les caractéristiques physico-chimiques des poudres et leur aptitude au frittage est étudiée. Il apparaît alors que les deux procédés permettent l'obtention de pièces correctement densifiées présentant de faibles pertes magnétiques d'insertion. Tout écart à la stœchiométrie doit être évité, mais la détérioration des propriétés magnétiques n'est importante qu'à partir du moment où il y a présence dans le matériau d'une phase étrangère au grenat

Download or read book Elaboration tude et caract risation de couches minces dans les grenats de fer et d yttrium written by Bassel Abdel Samad and published by . This book was released on 2009 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le travail de thèse a commencé par l'élaboration des couches minces de grenat de fer et d'yttrium (YIG) au laboratoire DIOM de Saint-Etienne, par pulvérisation cathodique radio fréquence. Une centaine d'échantillons a été réalisée en faisant varier les conditions de dépôt : débit d'argon, débit d'oxygène, chauffage du substrat et recuit sous air et sous vide. La caractérisation magnéto-optique et magnétique des échantillons a été réalisée par l'étude de l'effet Faraday, de l'effet Kerr, le VSM permettant de vérifier les propriétés magnétiques des couches minces. L'état de surface des échantillons a été analysé par microscopie électronique à balayage. La mesure de l'épaisseur des couches est réalisée par un profilomètre. La technique de caractérisation par rétrodiffusion d'ions α (RBS) réalisée par une équipe du CNRS au Liban, a permis de déterminer la stœchiométrie des différents échantillons. L'état cristallin des échantillons a été réalisé par l'analyse de diffractions des rayons X, ces travaux ont abouti à certaines améliorations. Le travail présente également le design du circulateur coplanaire, l'élaboration des couches magnétiques, de la réalisation de la structure en salle blanche (Laboratoire Hubert Curien) et en finalité sur la caractérisation des dispositifs. Les circulateurs que nous avons réalisés présentent un effet non-réciproque très intéressant, y compris pour des épaisseurs de ferrite très faibles (8μm)

Download or read book Processus de germination d une seconde phase dans les grenats de fer et d yttrium substitu s written by Jean-Yves Laval and published by . This book was released on 1976 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: ASPECTS DES TRANSFORMATIONS DE PHASE DANS DES MATERIAUX MOINS CONNUS OU NON METALLIQUES, DESCRIPTION DE LA STRUCTURE DE GRENAT DE FER ET D'YTTRIUM SUBSTITUE EN LIAISON AVEC LEURS PROPRIETES MAGNETIQUES, METHODES D'ELABORATION DES GRENATS. MISE EN EVIDENCE DE 2 MODES DE GERMINATION DE LA MAGNETITE DANS LE GRENAT: GERMINATION HOMOGENE ET HETEROGENE. PROPOSITION ET ANALYSE D'UN MODELE IONIQUE DE GERMINATION HETEROGENE. ETUDE DU ROLE DU GADOLINIUM DANS LE PROCESSUS DE GERMINATION HETEROGENE DE LA MAGNETITE ET APPLICATION DU MODELE DE REARRANGEMENT IONIQUE A L'ENSEMBLE DE LA ZONE DE GERMINATION ET ETABLISSEMENT D'UNE STRUCTURE POUR CETTE ZONE.

Download or read book DISSOCIATION DES DISLOCATIONS DANS LES OXYDES DE STRUCTURE GRENAT written by Jacques Rabier and published by . This book was released on 1979 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: RAPPEL DES CARACTERISTIQUES DE LA STRUCTURE GRENAT ET DES PROPRIETES PHYSIQUES DU YIG. DESCRIPTION DU MONTAGE DE DEFORMATION HAUTE TEMPERATURE CONCU POUR ETUDIER LA PLASTICITE DES OXYDES. MODELE DE DISSOCIATION DES DISLOCATIONS DANS LA STRUCTURE GRENAT. ESSAIS DE DEFORMATION PLASTIQUE DES MONOCRISTAUX DE YIG REALISES PAR SOLLICITATION A VITESSE CONSTANTE ET PAR FLUAGE. ETUDE DE LA SOUS-STRUCTURE DE DEFORMATION PAR MICROSCOPIE ELECTRONIQUE EN TRANSMISSION. ETUDE DE LA DIFFUSION DES DEFAUTS MINORITAIRES ET DE L'INFLUENCE DE LA STOECHIOMETRIE SUR LES PROPRIETES MECANIQUES

Download or read book The Journal of Physics and Chemistry of Solids written by and published by . This book was released on 1975 with total page 846 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propri t s des monocristaux de grenat d yttrium et application l tude de filtres micro ondes accordables written by Bernard Desormiere and published by . This book was released on 1963 with total page 154 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ETUDE DU GERMANATE DE CALCIUM ET D YTTRIUM A STRUCTURE GRENAT DOPE A L EUROPIUM written by FABIENNE.. PELLE and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: ELABORATION, CARACTERISATION DU MATERIAU ET ETUDE STRUCTURALE. UTILISATION DES PROPRIETES DE SONDE STRUCTURALE PONCTUELLE DE L'ION LANTHANIDE POUR DETERMINER LA SYMETRIE DES SITES OCCUPES PAR LE LANTHANIDE A PARTIR DE L'INTERPRETATION DES SPECTRES OPTIQUES. ETUDE PAR SPECTROMETRIE MOESSBAUER DE LA REPARTITION QUANTITATIVE DE L'ION EU**(3+) ENTRE LES DEUX SITES CRISTALLOGRAPHIQUES. CALCUL DES PARAMETRES DE CHAMP CRISTALLIN ENVIRONNANT LE LANTHANIDE DANS LES DEUX SITES

Download or read book tude des transformations cristallines haute temp rature au dessus de 2000 K written by and published by . This book was released on 1972 with total page 508 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Magnetic Garnets written by Dr. Gerhard Winkler and published by . This book was released on 1981 with total page 760 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Zentralblatt f r Mineralogie written by and published by . This book was released on 1972 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On Induction written by Michael 1791-1867 Faraday and published by Legare Street Press. This book was released on 2021-09-09 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important and is part of the knowledge base of civilization as we know it. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. To ensure a quality reading experience, this work has been proofread and republished using a format that seamlessly blends the original graphical elements with text in an easy-to-read typeface. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.

Download or read book IBZ written by Otto Zeller and published by . This book was released on 1976 with total page 1282 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geology and Metallogeny of the Chapais Chibougamau Mining District written by Pierre Pilote and published by [Chibougamau? Québec] : Institut canadien des mines Chapais-Chibougamau. This book was released on 1998-01-01 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Critical Metals Handbook written by Gus Gunn and published by John Wiley & Sons. This book was released on 2014-01-06 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mankind is using a greater variety of metals in greater quantities than ever before. As a result there is increasing global concern over the long-term availability of secure and adequate supplies of the metals needed by society. Critical metals, which are those of growing economic importance that might be susceptible to future scarcity, are a particular worry. For many of these we have little information on how they are concentrated in the Earth’s crust, how to extract them from their ores, and how to use, recycle and dispose of them effectively and safely. Published with the British Geological Survey, the Critical Metals Handbook brings together a wealth of knowledge on critical metals and provides a foundation for improving the future security and sustainability of critical metal supplies. Written by international experts, it provides a unique source of authoritative information on diverse aspects of the critical metals, including geology, deposits, processing, applications, recycling, environmental issues and markets. It is aimed at a broad non-specialist audience, including professionals and academics working in the exploration and mining sectors, in mining finance and investment, and in mineral processing and manufacturing. It will also be a valuable reference for policy makers concerned with resource management, land-use planning, eco-efficiency, recycling and related fields.

Download or read book The Rare Earth Elements written by David A. Atwood and published by John Wiley & Sons. This book was released on 2013-02-19 with total page 994 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lanthanides are of great importance for the electronic industries, this new book (from the EIBC Book Series) provides a comprehensive coverage of the basic chemistry, particularly inorganic chemistry, of the lanthanoid elements, those having a 4f shell of electrons. A chapter is describing the similarity of the Group 3 elements, Sc, Y, La, the group from which the lanthanoids originate and the group 13 elements, particularly aluminum, having similar properties. Inclusion of the group 3 and 13 elements demonstrates how the lanthanoid elements relate to other, more common, elements in the Periodic Table. Beginning chapters describe the occurrence and mineralogy of the elements, with a focus on structural features observed in compounds described in later chapters. The majority of the chapters is organized by the oxidation state of the elements, Ln(0), Ln(II), Ln(III), and Ln(IV). Within this organization the chapters are further distinguished by type of compound, inorganic (oxides and hydroxides, aqueous speciation, halides, alkoxides, amides and thiolates, and chelates) and organometallic. Concluding chapters deal with diverse and critically important applications of the lanthanoids in electronic and magnetic materials, and medical imaging.

Download or read book Bulletin de l Institut international du froid written by International Institute of Refrigeration and published by . This book was released on 1980 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: Some numbers called Special issue and consist of summaries of papers to be presented at the International Congresses of Refrigeration.

Download or read book Precambrian Banded Iron Formations written by Y.P. Mel'nik and published by Elsevier. This book was released on 1982-01-01 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Precambrian Banded-Iron-Formations