Investigation of the magnetism and magnetocaloric effect in the R2CoAl3 (R = Gd, Tb, Dy, and Ho) compounds

The crystal structure, magnetic properties and magnetocaloric effect (MCE) of R2CoAl3 (R = Gd, Tb, Dy, and Ho) compounds have been investigated. The refinement results proved that the samples are crystallized in MgCu2-type structure with space group of Fd-3m. The R2CoAl3 compounds undergo a paramagnetic to ferromagnetic phase transition (second ordered) and exhibit considerable reversible MCE around Curie temperatures TC of 70 K, 47 K, 33 K, and 20 K for R = Gd, Tb, Dy, and Ho, respectively. For the magnetic field change of 0-7 T, the maximum values of magnetic entropy change (-Delta S-M(max)) are 16.2, 10.6, 9.4, 16.5 J/kg K for R = Gd, Tb, Dy, and Ho, respectively. The considerable MCE with no hysteresis and wide working temperature span suggests that these materials could be promising candidates for magnetic refrigeration. (C) 2017 Elsevier B.V. All rights reserved.