Structural, atomic Hirschfeld surface, magnetic and magnetocaloric properties of SmNi5 compound

Abstract

The SmNi5 intermetallic compound has been investigated by arc-melting. Powder X-ray diffraction analysis and Rietveld refinement revealed that the sample crystallized in the hexagonal CaCu5-type structure P6/mmm space group with the following lattice parameters: a = 4.9203 (1) Å, c = 3.9662 (1) Å. These lattice parameters for the compound are in good agreement with previous theoretical result and experimental data. The EDX analysis has been performed to confirm the composition of this compound. The chemical bonding in SmNi5 was analyzed using atomic Hirshfeld surfaces, and this analysis supports the presence of the structural elements and the coordination of Sm (1a), Ni (2c) and Ni (3 g). This study indicates the different types of interatomic interactions between the Sm and Ni atoms and the weak interactions between Sm–Sm atoms were also observed along the c axis. The magnetic properties and magnetocaloric effect (MCE) have been established by the magnetization and isothermal magnetization of different temperature measurements. The magnetization curve as a function of temperature shows a magnetic transition from ferromagnetic to paramagnetic state at the Curie temperature TC = 29 K. We have studied the MCE phenomena in the vicinity of magnetic phase transitions in terms of magnetic entropy change. The temperature dependence of the magnetization, the magnetic entropy changeΔSM, as well as the relative cooling power around the second-order magnetic transition and the Arrott plots for the alloys are reported.