Ab Initio Investigations of Structural and Magnetic properties of Cr-doped Ni-Co-Mn-Sn Heusler alloys

摘要

Ab initio calculations were performed to investigate composition dependences of crystal lattice parameters, magnetic moments, bulk modulus, magnetic exchange parameters in Ni_(2-y)Co_yMn_(1.5-x)Cr_xSn_(0.5) (y=0.2, 0.4; 0.0 ≤x ≤0.4) Heusler alloys. It was shown that increasing in Cr content (x) firstly leads to the increasing of lattice parameter, but then - to the decreasing. The strongest ferromagnetic (FM) interaction for Ni_(1.6)Co_(0.4)Mn_(1.4)Cr_(0.1)Sn_(0.5) is the nearest-neighbor (NN) interaction between Co and Mn_1. While, the strongest antiferromagnetic (AFM) interaction is observed between the NN Mn_1-Cr atoms and it is equal to -15meV. Total magnetic moment of Ni_(2-y)Co_yMn_(1.5-x)Cr_xSn_(0.5) (y=0.2, 0.4; 0.0 ≤x≤0.4) takes value from 6.1 μ_B to 6.6 μ_B.