Influence of microstructural defects on the martensitic transformation and on the magnetic properties of ni-based heusler alloys
- Fernando Plazaola Muguruza Director
- José Ángel García Martínez Director
Universitat de defensa: Universidad del País Vasco - Euskal Herriko Unibertsitatea
Fecha de defensa: 14 de de març de 2019
- José Manuel Barandiarán García President/a
- José Ignacio Pérez de Landazábal Secretari/ària
- Roberto Mantovani Vocal
Tipus: Tesi
Resum
The thesis deals with the effect that microstructural defects have on the magneticproperties and martensitic transformation in Ni-Mn-Z (Z = Ga, In, Sn)and Ni-Fe-Ga alloys. For this purpose, along with the standard characterizationtechniques, two additional specific nuclear techniques have been employed; 119SnMössbauer Spectroscopy and Positron Annihilation Lifetime Spectroscopy, PALS.For the consecution of this thesis one PALS spectrometer has been designed, builtand optimized. For offline emission Mössbuauer experiments, a setup has been alsobuilt for measuring ion implanted samples. Finally, a high temperature annealingfurnace has been designed and built to carry out the annealing of powdered samplesunder controllable atmosphere. // The thesis deals with the effect that microstructural defects have on the magneticproperties and martensitic transformation in Ni-Mn-Z (Z = Ga, In, Sn)and Ni-Fe-Ga alloys. For this purpose, along with the standard characterizationtechniques, two additional specific nuclear techniques have been employed; 119SnMössbauer Spectroscopy and Positron Annihilation Lifetime Spectroscopy, PALS.For the consecution of this thesis one PALS spectrometer has been designed, builtand optimized. For offline emission Mössbuauer experiments, a setup has been alsobuilt for measuring ion implanted samples. Finally, a high temperature annealingfurnace has been designed and built to carry out the annealing of powdered samplesunder controllable atmosphere.