Understanding the origin of the magnetocaloric effects in substitutional Ni-Mn-Sb-Z(Z=Fe,Co,Cu) compounds: Insights from first-principles calculations

Abstract

Ni-Mn based ternary Heusler compounds have drawn attentions lately as significant magnetocaloric effects in some of them have been observed. Substitution of Ni and Mn by other 3d transition metals in controlled quantity have turned out to be successful in enhancing the effect and bring the operational temperatures closer to the room temperature. Using density functional theory calculations, in this work, we have systematically explored the roles of various factors such as site occupancies, magnetic interactions, and compositions associated with the constituents of Mn-excess Ni2MnSb Heusler compounds upon substitution of Ni and/or Mn by 3d transition metals Fe, Co and Cu. Our calculations unveiled the physics behind the variations of physical properties associated with the magneto-caloric effects, and thus interpreted the available experimental results successfully. The work also provided important information on the compounds and the composition ranges where significant magneto-caloric effects may be realised and further experimental investigations need to be done.

A unified physical mechanism for martensitic phase transition and ductility in Ni–Mn-based ferromagnetic shape memory alloys: the case of Cu-doped Ni2MnGa

“…Notably, it is not a unique instance, but has its counterpart. When Cu was introduced to Ni-rich Ni–Mn–X (X = In, Sn, Sb) alloys 20–22 or Mn-rich Mn–Ni–In/Sn alloys, 23,24 similar change tendencies of martensitic phase transition temperature and mechanical properties were experimentally observed. These results indicate that there exists a unified physical mechanism for martensitic phase transition and ductility in Cu-doped Ni–Mn-based FSMAs.…”

“…, metallic or covalent bonding. 19,20,29,30 Previous studies verified their validity and they are still widely used to discuss the phase stability and mechanical properties of Ni–Mn-based Heusler alloys.…”

“…The validity of these two parameters has been verified in Ni–Mn-based Heusler alloys. 19,20,29,30 Currently, they are still widely used to evaluate the mechanical properties of Ni–Mn-based Heusler alloys.…”

Alloying Effect on Transformation Strain and Martensitic Transformation Temperature of Ti-Based Alloys from Ab Initio Calculations

“…Therefore, the increase in the martensite temperature is consistent with the decrease in elastic modulus. The relationship proposed by Ren and Otsuka [76] has been widely accepted for investigating the M s for TiNi-based [50,77,78], Cu−Al−Mn [79], and Ni-based [49,[80][81][82] systems. These studies [49,50,[77][78][79][80][81][82] have treated elastic modulus as one of the indicators to predict martensite temperature.…”

Simultaneous improvement of martensitic phase transition and ductility in Cu-doped and/or alloyed all-d-metal Ni2MnTa Heusler compounds

“…Previous studies in Cu-doped and/or alloyed Ni–Mn-based compounds have demonstrated its reliability. 32–34 The k -point mesh is 15 × 15 × 15 and all calculations are spin-polarized in this study. For reproducibility, pseudopotential configurations for Cu doped and/or alloyed Ni 2 MnTa compounds were selected as follows: Ni: Ni_80.otfg, Mn: Mn_80.otfg, Ta: Ta_80.otfg, and Cu: Cu_80.otfg.…”