2024-03-28T14:50:15Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1488492019-05-09T09:30:32Zcom_10261_31com_10261_3col_10261_410
Enhanced magnetocaloric effect by the rare earth polarization due to the exchange with a transition metal. Study of GdCrO4
Palacios, Elias
Burriel, Ramón
Sáez-Puche, R.
Dos Santos-García, Antonio J.
Fernández-Martínez, F.
Tomasi, Corrado
Resumen del trabajo presentado a la 20th International Conference on Solid Compounds of Transition Elements, celebrada del 11 al 15 de abril de 2016 en Zaragoza (España).
The magnetocaloric effect of a paramagnetic salt has been used long time ago as the physical mechanism for cooling below 1 K. For weak fields or relatively high temperatures the isothermal entropy change ΔST is proportional to the variation of the squared magnetic field. Therefore, a strong preexisting field increases ΔST for a given external field variation ΔB. In magnetic insulators of rare earth R and transition metal M atoms, the R-R exchange interaction is usually much weaker than the R-M exchange and this one is much weaker than the M-M exchange. At intermediate temperatures between the complete ordering of R\'s and M\'s, the R-M exchange acts as an additional constant external field. The effect was observed time ago in antiferromagnetic perovskites. Now, we study the ferromagnetic case of GdCrO4 zircon polymorph, where an exchange field about 7 T adds on to the external field to produce a large magnetocaloric effect |ΔST| > 20 J/kg·K for an increment ΔB from 0 to 9 T, over a wide temperature range 5 K < T < 35 K, reaching a maximum of 29 J/kg·K at 22 K. These values are very useful regarding to applications for liquefying hydrogen or natural gas as they, at least, double the cooling capacity of the materials (GGG, DGAG, ...) used in recent prototypes of magnetic refrigerators.
Peer Reviewed
2017-04-26T09:02:01Z
2017-04-26T09:02:01Z
2016
2017-04-26T09:02:03Z
comunicación de congreso
http://purl.org/coar/resource_type/c_5794
SCTE (2016)
http://hdl.handle.net/10261/148849
Sí
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