Now showing items 1-12 of 12

    • Entropy change caused by martensitic transformations of ferromagnetic shape memory alloys 

      L'vov, Victor A.; Cesari, Eduard; Kosogor, Anna; Torrens Serra, Joan; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      In this paper, our most recent findings on the influence of magnetic order on the main transformational caloric and elastic properties of shape memory alloys (SMAs) are reviewed. It is argued that ferromagnetic order has ...
    • Experimental observation of vacancy-assisted martensitic transformation shift in Ni-Fe-Ga alloys 

      Unzueta, Iraultza; Alonso de Robador Lorente, Daniel; Cesari, Eduard; Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; García, José Ángel; Plazaola, Fernando (American Physical Society, 2019)   Artículo / Artikulua  OpenAccess
      Positron annihilation lifetime spectroscopy is used to experimentally demonstrate the direct relationship between vacancies and the shift of the martensitic transformation temperature in a Ni55Fel7Ga28 alloy. The evolution ...
    • Giant direct and inverse magnetocaloric effect linked to the same forward martensitic transformation 

      Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Sánchez-Alarcos Gómez, Vicente Upna; Beato López, Juan Jesús Upna; Rodríguez Velamazán, José Alberto; Sánchez Marcos, J.; Gómez Polo, Cristina Upna; Cesari, Eduard (Springer Nature, 2017)   Artículo / Artikulua  OpenAccess
      Metamagnetic shape memory alloys have aroused considerable attraction as potential magnetic refrigerants due to the large inverse magnetocaloric effect associated to the magnetic-field-induction of a reverse martensitic ...
    • Identification of a Ni-vacancy defect in Ni-Mn-Z (Z = Ga, Sn, In): an experimental and DFT positron-annihilation study 

      Unzueta, Iraultza; Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Zabala, Nerea; García, José Ángel; Plazaola, Fernando (American Physical Society, 2019)   Artículo / Artikulua  OpenAccess
      By means of experimental positron-annihilation-lifetime measurements and theoretical density functional theory (DFT) positron-lifetime calculations, vacancy-type defects in Ni50Mn50−xSnx (x = 25, 20, 15, 13, 10) and ...
    • Influence of microstructure in the martensitic transformation and in the physical and magnetic properties in metamagnetic shape memory alloys 

      López García, Javier Upna (2019)   Tesis doctoral / Doktoretza tesia  OpenAccess
      In this work we have focused in the study of the influence of the microstructure in metamagnetic shape memory alloys (Ni-Mn-In and Ni-Mn-Sn systems) together with the effect of Co-doping, in order to gain insight into these ...
    • Long-range atomic order and entropy change at the martensitic transformation in a Ni-Mn-In-Co metamagnetic shape memory alloy 

      Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Cesari, Eduard; Rodríguez Velamazán, José Alberto (MDPI, 2014)   Artículo / Artikulua  OpenAccess
      The influence of the atomic order on the martensitic transformation entropy change has been studied in a Ni-Mn-In-Co metamagnetic shape memory alloy through the evolution of the transformation temperatures under high-temperature ...
    • Low field magnetic and thermal hysteresis in antiferromagnetic dysprosium 

      Liubimova, Iuliia; Corró Moyá, Miguel; Torrens Serra, Joan; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Kustov, Sergey (MDPI, 2017)   Artículo / Artikulua  OpenAccess
      Magnetic and thermal hysteresis (difference in magnetic properties on cooling and heating) have been studied in polycrystalline Dy (dysprosium) between 80 and 250 K using measurements of the reversible Villari effect and ...
    • Magnetic transition in nanocrystalline soft magnetic alloys analyzed via ac inductive techniques 

      Gómez Polo, Cristina Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Vázquez, M.; Hernando, A. (American Physical Society, 2004)   Artículo / Artikulua  OpenAccess
      The magnetic transition in a FeSiBCuNb nanocrystalline alloy, associated with the decoupling of ferromagnetic crystallites around the Curie point of the residual amorphous matrix, is analyzed in this work through the ...
    • Magnetocaloric effect enhancement driven by intrinsic defects in a Ni45Co5Mn35Sn15 alloy 

      Sánchez-Alarcos Gómez, Vicente Upna; López García, Javier Upna; Unzueta, Iraultza; Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Beato López, Juan Jesús Upna; García, José Ángel; Plazaola, Fernando; Rodríguez Velamazán, José Alberto (Elsevier, 2019)   Artículo / Artikulua
      The influence of mechanically-induced defects on the magnetostructural properties is analyzed in a Ni-Co-Mn-Sn alloy subjected to soft milling and subsequent annealing treatments. It is found that, opposite to what occurs ...
    • Outstanding role of the magnetic entropy in arrested austenite in an ordered Ni45Mn36.7In13.3Co5 metamagnetic shape memory alloy 

      Pérez de Landazábal Berganzo, José Ignacio Upna; Recarte Callado, Vicente Upna; Sánchez-Alarcos Gómez, Vicente Upna; Jiménez Ruiz, M.; Cesari, Eduard (Elsevier, 2019)   Artículo / Artikulua
      The relevance of the entropy and in particular the outstanding role of the magnetic contribution is analyzed in a non-equilibrium arrested austenite phase in a Ni 45 Mn 36.7 In 13.3 Co 5 metamagnetic shape memory alloy. ...
    • Routes for enhanced magnetism in Ni-Mn-In metamagnetic shape memory alloys 

      López García, Javier Upna; Sánchez-Alarcos Gómez, Vicente Upna; Recarte Callado, Vicente Upna; Pérez de Landazábal Berganzo, José Ignacio Upna; Fabelo, O.; Cesari, Eduard; Rodríguez Velamazán, José Alberto (Elsevier, 2019)   Artículo / Artikulua
      The authors provide in-depth physical insight into the enhancement of the magnetic properties of metamagnetic shape memory alloys produced by thermal treatment and cobalt doping. They use neutron scattering to study the ...
    • Tailoring the structural and magnetic properties of Co-Zn nanosized ferrites for hyperthermia applications 

      Gómez Polo, Cristina Upna; Recarte Callado, Vicente Upna; Cervera Gabalda, Laura María Upna; Beato López, Juan Jesús Upna; López García, Javier Upna; Rodríguez Velamazán, José Alberto; Ugarte Martínez, María Dolores Upna; Mendonça, E. C.; Duque, J. G. S. (Elsevier, 2018)   Artículo / Artikulua
      A comparative study of the magnetic properties (magnetic moment, magnetocrystalline anisotropy) and hyperthermia response in Co-Zn spinel nanoparticles is presented. The CoxZn1-xFe2O4 nanoparticles (x = 1, 0.5, 0.4, 0.3, ...