Abstract
Structural, magnetic and electronic properties of a series of Ni2Mn1−xCrxGa Heusler alloys have been studied by means of ab initio calculations and Monte Carlo simulations. The optimized lattice parameters of all investigated compositions are close to 5.81 Å and weakly depend on Cr excess. The martensitic transformation in Ni-Mn-Cr-Ga alloys occurs in all compositional range. Tetragonal distortions weakly depend on Cr concentration. Besides, an increase in energy difference between austenite and martensite with increasing Cr content was observed. For electronic and magnetic properties, it was observed that Ni2Mn1−xCrxGa demonstrate the metallic behavior. Using the SPR-KKR calculations of magnetic exchange constants, we have shown that the largest contribution to the total exchange energy is associated between nearest neighbor Ni-Mn pair. These inter-sublattice interactions in austenitic phase are higher then intra-sublattice interactions (Ni-Ni and Mn(Cr)-Mn(Cr)). Estimated Curie temperatures for Ni2Mn1−xCrxGa are found to decrease with increasing Cr content. All obtained results are in good agreement with experimental data.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call