Magnetocaloric effect enhancement driven by intrinsic defects in a Ni45Co5Mn35Sn15 alloy
Date
2019Author
Version
Acceso abierto / Sarbide irekia
Type
Artículo / Artikulua
Version
Versión aceptada / Onetsi den bertsioa
Project Identifier
ES/1PE/MAT2015-65165
Impact
|
10.1016/j.jallcom.2018.10.016
Abstract
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 in Ni-Mn-Sn ternary alloys, the annealing treatment affects the magnetic properties in a different way in martensite and in austenite. In particular, the saturation magnetizatio ...
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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 in Ni-Mn-Sn ternary alloys, the annealing treatment affects the magnetic properties in a different way in martensite and in austenite. In particular, the saturation magnetization significantly increases in martensite after annealing whereas just a very slight variation is observed in austenite. This leads to the interesting fact that the presence of microstructural defects, far for worsening, makes the magnetocaloric effect to be higher in the as-milled state than after annealing. This behavior is explained as the result of the combination of the effect of defects on the Mn-Mn distance, the effect of Co on the magnetic exchange coupling between Mn atoms, and the effect of defects on the vibrational entropy change at the martensitic transformation. [--]
Subject
Defects,
Magnetocaloric effect,
Ni-Mn-Sn-Co,
Vibrational entropy
Publisher
Elsevier
Published in
Journal of Alloys and Compounds, 774 (2019) 586-592
Departament
Universidad Pública de Navarra. Departamento de Física /
Nafarroako Unibertsitate Publikoa. Fisika Saila /
Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa. INAMAT2 - Institute for Advanced Materials and Mathematics
Publisher version
Sponsorship
This work has been carried out with the financial support of the Spanish Ministerio de Economía y Competitividad (Projects number MAT2015-65165-C2-R ) and of the Basque Government (Grant No. IT-1005-16). J. López-García acknowledges ILL for his Ph. D. contract and I. Unzueta also wants to thank the Basque Government Grant No. PRE-2014-1-214.