Magnetic properties and magnetocaloric effects in (Ho1-xYx)5Pd2 compounds

The crystal structure, magnetic and magnetocaloric properties of (Ho1-xYx)(5)Pd-2 (x = 0, 0.25, and 0.5) compounds are investigated. All the compounds crystallize in a cubic Dy5Pd2-type structure with the space group Fd3m and undergo a second order transition from spin glass (SG) state to paramagnetic (PM) state. The spin glass transition temperatures T-g decrease from 26 K for x = 0 to 13 K for x = 0.5. In the PM region, the reciprocal susceptibilities for all the compounds obey the Curie-Weiss law. The paramagnetic Curie temperatures (theta(p)) for Ho5Pd2, (Ho0.75Y0.25)(5)Pd-2, and (Ho0.5Y0.5)(5)Pd-2 are determined to be 32 K, 30 K, and 22 K, respectively, and the corresponding effective magnetic moments (mu(eff)) are 10.8 mu(B)/Ho, 10.3 mu(B)/RE, and 7.5 mu(B)/RE, respectively. Magnetocaloric effect (MCE) is anticipated according to the Maxwell relation, based on the isothermal magnetization curves. For a magnetic field change of 0-5 T, the maximum values of the isothermal magnetic entropy change -Delta S-M of the (Ho1-xYx)(5)Pd-2 (x = 0, 0.25, and 0.5) compounds are determined to be 11.5 J.kg(-1).K-1, 11.1 J.kg(-1).K-1, and 8.9 K J.kg(-1).K-1, with corresponding refrigerant capacity values of 382.3 J.kg(-1), 336.2 J.kg(-1), and 242.5 J.kg(-1), respectively.