Producció i anàlisi d’aliatges Heusler no estequiomètrics: Ni-Mn-Sn-(Co,Fe)

Magnetic memory alloys are a subset of shape memory materials that respond to the application of external magnetic fields. These materials are currently gaining more and more interest, given their properties, for use in actuators, materials with induced deformations or to take advantage of their mag...

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Detalles Bibliográficos
Autor: Deltell, Àlex
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2020
País:España
Institución:CBUC, CESCA
Repositorio:TDR. Tesis Doctorales en Red
OAI Identifier:oai:www.tdx.cat:10803/669826
Acceso en línea:http://hdl.handle.net/10803/669826
Access Level:acceso abierto
Palabra clave:Aliatge Heusler
Aleaciones Heusler
Heusler alloys
Materials magnètics
Materiales magnéticos
Magnetic materials
Cristal·lografia
Crystallography
Refrigeració magnètica
Refrigeración magnética
Magnetic cooling
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Descripción
Sumario:Magnetic memory alloys are a subset of shape memory materials that respond to the application of external magnetic fields. These materials are currently gaining more and more interest, given their properties, for use in actuators, materials with induced deformations or to take advantage of their magnetocaloric effect (direct or reverse) to implement magnetic refrigeration systems. In that last application, it is interesting that the magnetocaloric effect is placed close to ambient temperatures or higher, depending of the application. The purpose of this work is the production and characterization of non-stoichiometric Heusler alloys based on a composition with nickel, manganese, and tin, with cobalt or iron doping. These alloys are produced with magnetic refrigeration applications in mind. The effect of doping will be identified, both on the crystalline structure of the alloys and on the phase transition temperatures, thermodynamic or magnetocaloric parameters. The production will be done with arc melting techniques, to produce the bulk and then melt spinning, conforming the alloys as ribbons.