Effect of Gd polarization on the large magnetocaloric effect of GdCrO4 in a broad temperature range

Palacios, E. (Universidad de Zaragoza) ; Tomasi, C. ; Sáez-Puche, R. ; Dos Santos-García, A.J. ; Fernández-Martínez, F. ; Burriel, R. (Universidad de Zaragoza)

Resumen: The ferromagnetic zircon-type phase of GdCrO4 presents high values for the magnetocaloric (MC) parameters. This compound has large isothermal entropy changes ¿ST under the magnetic field action in a wide temperature range, from 5 to 35 K, reaching a maximum |¿ST|=29.0±0.1J/kgK at 22 K, for a field increment ¿B=9 T. It orders ferromagnetically at TC=21.3K via the Cr-Cr exchange interaction and shows a second transition at 4.8 K due to the ordering of the Gd sublattice. The large MC effect is enhanced by the polarization of the Gd3+ ions by the Cr5+ ones via a weaker Gd-Cr interaction. This effect is an interesting feature to be considered in the search for new compounds with a high MC effect in the range of liquid hydrogen or natural gas, regarding the liquefaction of gases by magnetization-demagnetization cycles. This paper contains experimental measurements of magnetization, heat capacity, and direct determinations of the MC effect. The magnetic contribution to the heat capacity Cm has been obtained after subtracting the lattice component. Approximate values for the exchange constants J1 (Cr-Cr) and J3 (Gd-Cr) have been deduced from Cm.

Idioma: Inglés

DOI: 10.1103/PhysRevB.93.064420

Año: 2016

Publicado en: Physical Review B 93, 6 (2016), 064420 [8 pp]
ISSN: 2469-9950

Factor impacto SCIMAGO: 0.0 - Electronic, Optical and Magnetic Materials - Condensed Matter Physics

Financiación: info:eu-repo/grantAgreement/ES/DGA/E100
Financiación: info:eu-repo/grantAgreement/ES/MINECO/MAT2013-44063-R

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Física Materia Condensada (Dpto. Física Materia Condensa.)