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

Abstract

Abstract The crystal structure, magnetic and magnetocaloric properties of (Ho1−x Y x )5Pd2 (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 ( θ p ) for Ho5Pd2, (Ho0.75Y0.25)5Pd2, and (Ho0.5Y0.5)5Pd2 are determined to be 32 K, 30 K, and 22 K, respectively, and the corresponding effective magnetic moments ( μ eff ) are 10.8 μ B /Ho, 10.3 μ B /RE, and 7.5 μ 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 − Δ S M of the (Ho1−x Y x )5Pd2 (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.