Study of the magnetocaloric effect in intermetallics RTX (R = Nd, Gd; T = Sc, Ti; X = Si, Ge). (July 2019)

• Record Type: Journal Article
• Authors: Herrero, A.; Oleaga, A.; Manfrinetti, P.; Provino, A.; Salazar, A.
• Is Part Of: Intermetallics. Volume 110(2019:Jul.)
• Publication Date: 2019-07
• Subjects: Rare-earth scandium silicides -- Rare-earth scandium germanides -- Magnetic properties -- Magnetocaloric effect -- Magnetorefrigerant materials; Intermetallic compounds -- Metallography -- Periodicals; Metallic glasses -- Periodicals; Composés intermétalliques -- Métallographie -- Périodiques; 669.94
• DOI: 10.1016/j.intermet.2019.106495
• Languages: English
• ISSNs: 0966-9795

Abstract

Abstract: A detailed study of the magnetocaloric properties of six compounds of the intermetallic family RTX (R = Nd, Gd; T = Sc, Ti; X = Si, Ge) has been undertaken: NdScSi, NdScGe, GdScSi, GdScGe, GdSc(Si0.5 Ge0.5 ) and Gd(Sc0.5 Ti0.5 )Ge. The magnetic entropy changes at the Curie temperature T C and the refrigerant capacities signal that they are competitive magnetocaloric materials, showing that an improvement can be obtained by tuning the composition, as Gd(Sc0.5 Ti0.5 )Ge presents the best properties. These magnetocaloric variables fulfill the scaling equations with the critical parameters corresponding to the universality classes to which the ferromagnetic transitions belong (3D-XY, 3D-Heisenberg, Mean field). For each compound, a universal curve has been found for the rescaled magnetic entropy changes obtained at different applied fields, whose behavior at temperatures below T C indicate the relevance of taking into account the demagnetization field. Finally, it has been demonstrated that the rescaled magnetic entropy changes for the compounds which share the same universality class collapse onto a single universal curve. Highlights: NdScGe, NdScSi, GdScSi, GdScGe, GdSc(Si0.5 Ge0.5 ), Gd(Sc0.5 Ti0.5 )Ge are compared. Refrigerant capacities show that they are competitive magnetocaloric materials. Magnetocaloric variables scale after the corresponding critical exponents. Universal curves show that the demagnetization field is relevant. A universal curve is obtained for materials which share the universality class.