Designing shape-memory Heusler alloys from first-principles

Abstract

A generalized Irving-Kirkwood formula for the calculation of stress in molecular dynamics models J. Chem. Phys. 137, 134104 (2012) Effect of temperature, strain, and strain rate on the flow stress of aluminum under shock-wave compression J. Appl. Phys. 112, 073504 (2012) Colossal low-frequency resonant magnetomechanical and magnetoelectric effects in a three-phase ferromagnetic/elastic/piezoelectric composite Appl.The phase diagrams of magnetic shape-memory Heusler alloys, in particular, ternary Ni-Mn-Z and quarternary (Pt, Ni)-Mn-Z alloys with Z ¼ Ga, Sn, have been addressed by density functional theory and Monte Carlo simulations. Finite temperature free energy calculations show that the phonon contribution stabilizes the high-temperature austenite structure while at low temperatures magnetism and the band Jahn-Teller effect favor the modulated monoclinic 14M or the nonmodulated tetragonal structure. The substitution of Ni by Pt leads to a series of magnetic shape-memory alloys with very similar properties to Ni-Mn-Ga but with a maximal eigenstrain of 14%.

First-principle investigation of electronic structure, magnetism and phase stability of Heusler-type Pt2−Mn1+Ga alloys

“…Up to now, many investigations on the materials with the martensitic transformation have been done based on the first-principles calculations. The martensitic transformation and magnetic properties obtained based on these calculations are in good agreement with the experimental results [6][7][8][9][10][11][12][13]. Thus, the first-principles calculations have become an effective method to search for new-type FSMAs.…”

Advanced materials for solid-state refrigeration

“…There are, however, still few works with predictive character. By combining density functional modelling and Monte Carlo simulations Siewert et al 94 suggested that Pt-doping in Ni-Mn-based Heusler alloys improves the performances of these alloys, in particular their magnetocaloric properties 95 . Furthermore, in recent works, models based on first principles have been used to predict a giant electrocaloric effect in LiNbO 3 96 and both, electrocaloric 97 and elastocaloric 98 effects in Ba 0.55 Sr 0.5 TiO 3 .…”

Ab initio study of effect of Co substitution on the magnetic properties of Ni and Pt-based Heusler alloys

“…Except Pt 2 MnSn, the other three materials, namely Ni 2 MnGa, Ni 2 FeGa, Pt 2 MnGa, of the lower panel are already reported to undergo martensite transition. 10,30,31 Now we plot ( Figure-3 to Figure-6 SMA property (x=2.00).…”

“…It has been observed that both T M and T C values are very much dependent on the composition of a particular Heusler alloy. [4][5][6][7][8][9][10][11][12][13][14][15][16] There is also another category of full Heusler alloys, which are known to be metallic for one kind of spin channel and insulator for the other kind of spin channel because of their very high spin polarization (HSP) at the Fermi level. They are often called as half metallic Heusler alloys.…”