Fig. 4
From: Beyond a phenomenological description of magnetostriction
Ab initio calculations of the lattice and magnetic stress. a The mode resolved lattice stress, \(\sigma _i^{\rm{ph}}\), along lattice directions, i = a and c, calculated ab initio for a non-equilibrium phonon population. b The ab initio calculated total energies vs. c/a ratio for FePt in the ferromagnetic (FM, blue circles) and paramagnetic (PM, red circles) phase at constant volume. Calculations in the full a-, and c-plane (not shown) determine the lattice parameters change to Δa/a = +0.25% and Δc/c = −0.53% when moving from the global energy minimum (not shown) of the ferromagnetic to the paramagnetic phase. We note that the calculated ferromagnetic ground-state value of c/a = 0.964 is in good agreement with c/a = 0.972 ± 0.003 measured at room temperature (see Supplementary Figure 3c)
