Elastic and Magnetoelastic Properties of Fe-Rich Tetragonal Y–Fe Compounds: Phenomenology and Electron Theory

To study the strain effects on the lattice stability and magnetic anisotropy (MA) of Fe-rich tetragonal Y-Fe compounds, elastic constants of Y
₂
Fe
₁₄
B-and YFe
₁₂
-type compounds were calculated in the first principles, and MA of impurity-doped YFe
₁₂
with tetragonal lattice strain was calculated in a real-space tight-binding method. It has been found that the YFe
₁₂
-type compounds are elastically softer than Y
₂
Fe
₁₄
B, and that the uniaxial MA of Co-doped YFe
₁₂
may be increased by decreasing c/a, where c and a are the lattice constants along c-axis and within ab-plane, respectively.