Electronic structures, magnetic properties, and martensitic transformation in all-d-metal Heusler-like alloys Cd₂MnTM (TM = Fe, Ni, Cu)*

Abstract

The electronic structures, magnetic properties, and martensitic transformation in all-d-metal Heusler-like alloys Cd2MnTM (TM = Fe, Ni, Cu) were investigated by the first-principles calculations based on density-functional theory. The results indicate that all three alloys are stabilized in the ferromagnetic L21-type structure. The total magnetic moments mainly come from Mn and Fe atoms for Cd2MnFe, whereas, only from Mn atoms for Cd2MnNi and Cd2MnCu. The magnetic moment at equilibrium lattice constant of Cd2MnFe (6.36 μ B) is obviously larger than that of Cd2MnNi (3.95 μ B) and Cd2MnCu (3.82 μ B). The large negative energy differences (ΔE) between martensite and austenite in Cd2MnFe and Cd2MnNi under tetragonal distortion and different uniform strains indicate the possible occurrence of ferromagnetic martensitic transformation (FMMT). The minimum total energies in martensitic phase are located with the c/a ratios of 1.41 and 1.33 for Cd2MnFe and Cd2MnNi, respectively. The total moments in martensitic state still maintain large values compared with those in cubic state. The study is useful to find the new all-d-metal Heusler alloys with FMMT.

High-throughput design of magnetic materials

“…As the mechanical properties of all-d-metal Heusler compounds are expected to be better due to the d-d bonding, an interesting question is whether there exist promising candidates with enhanced caloric performance beyond the known Ni-Mn-Ti case [531]. There have been several studies focusing on Zn- [532], V- [533], and Cd-based [534] Heuslers, where possible martensitic transformation is assessed based on the evaluation of Bain paths. We note that in order to get enhanced MCE, the martensitic phase transition temperature is better aligned within the Curie temperature window [535].…”

Tailored martensitic transformation and enhanced magnetocaloric effect in all-d-metal Ni35Co15Mn33Fe2Ti15 alloy ribbons

“…At the same time, the prediction of crystal and electronic behaviors, phase stability, magnetic state, and possible martensitic transformation (MT) have also been calculated by the first principle calculations based on density functional theory (DFT) to explore the more all-d-metal Heusler alloys. [28,29] Most of them are focused on the modification of chemical composition, thermal treatment, and pressure in the all-d-metal alloys. For ribbon samples, little attention has been focused on the effect of linear wheel speed on MT and MCE.…”

Nonlinear optical properties in n-type quadruple δ-doped GaAs quantum wells

“…For instance, the density functional theory (DFT) can describe accurately the physical properties in multiple materials. [1][2][3][4][5] However, in this method, the calculation time efficiency in the processes is mainly determined by the diagonalization routines. [6] Besides, another approach, the Thomas-Fermi (TF) theory [7,8] allows the determination of the electronic structure with a very simple way in comparison to the DFT.…”