Giant magnetocaloric effect driven by first-order magnetostructural transition in cosubstituted Ni-Mn-Sb Heusler compounds: Predictions from ab initio and Monte Carlo calculations

Using density functional theory and a thermodynamic model [V. Sokolovskiy et al. Phys. Rev. B 86, 134418 (2012)] in this paper we provide an approach to systematically screen compounds of a given Heusler family to predict ones that can yield giant magnetocaloric effect driven by a first-order magnetostructural transition. We apply this approach to two Heusler series Ni2-xFexMn1+z-yCuySb1-z and Ni2-xCoxMn1+z-yCuySb1-z obtained by cosubstitution at Ni and Mn sites. We predict four new compounds with potentials to achieve the target properties. Our computations of the thermodynamic parameters relevant for magnetocaloric applications show that the improvement in the parameters in the predicted cosubstituted compounds can be as large as four times in comparison to the off-stoichiometric Ni-Mn-Sb and a compound derived by single substitution at the Ni site where magnetocaloric effects have been observed experimentally. This work establishes a protocol to select new compounds that can exhibit large magnetocaloric effects and demonstrate cosubstitution as a route for more flexible tunability to achieve outcomes better than the existing ones.

Automated summary

This paper presents a systematic screening approach for compounds in the Heusler family using density functional theory and a thermodynamic model, predicting four new compounds with potential for giant magnetocaloric effects. The study shows that cosubstitution can significantly improve thermodynamic parameters relevant for magnetocaloric applications compared to traditional substitution methods.