First-principles calculations of the spontaneous volume magnetostriction based on the magnetoelastic energy

Abstract

We present a simple methodology to compute the spontaneous volume magnetostriction with first-principles calculations on the basis of the magnetoelastic energy. This method makes use of deformations of the unit cell only at the ferromagnetic state. Hence, it does not require the difficult first-principles calculation of the equilibrium volume at the paramagnetic state. To validate this methodology, we apply it to body-centered cubic Fe and face-centered cubic Ni single crystals, finding consistent results with experiment and previous first-principles calculations. The simplicity and reliability of this approach could be exploited in the high-throughput screening of spontaneous volume magnetostriction, as well as associated quantities like isotropic magnetoelastic constants and isotropic magnetostrictive coefficients.

To compute spontaneous volume magnetostriction with the described method, the volume of the reference unit cell (unstrained state), from which the deformations are generated, should be equal to the equilibrium volume of the paramagnetic state. The volume of the reference state used in this work may not fulfill this condition. See more details in arXiv:2210.00791v2