Magnetostriction of the Fe-=SUB=-75-=/SUB=-Ga-=SUB=-25-x-=/SUB=-Z-=SUB=-x-=/SUB=- (Z=Al, Ge, Si) alloys: calculation by the magnetic torque method

This work presents an ab initio study of the effect of a small addition of the third element of III and IV groups on the elastic and magnetoelastic properties of Fe75Ga25 alloy. The dependencies of the tetragonal elastic modulus C', magnetoelastic constant -b1, and the tetragonal magnetostrictive constant λ001 on the concentration of the Z-element in the cubic crystal structures A2 and D03 were obtained with the help of the density functional theory and the magnetic torque method in Fe75Ga25-xZx (Z=Al, Ge, Si) alloys (0≤ x≤6 at.%). It is shown that the addition of Al and Si atoms leads to an increase in the tetragonal elastic modulus compared to the Fe75Ga25 binary alloy. A correlation was established in the dependence equilibrium lattice constants a0(x) and λ001(x) in the studied ternary alloys for the A2 structure. Keywords: tetragonal magnetostriction constant, magnetoelastic constant, tetragonal shear modulus, magnetic torque method.