Ab-initio based models for temperature-dependent magneto-chemical interplay in bcc Fe-Mn alloys

Abstract

Body-centered cubic (bcc) Fe-Mn systems are known to exhibit a complex and atypical magnetic behaviour from both experiments and 0 K electronic-structure calculations, which is due to the half-filled 3d-band of Mn. We propose effective interaction models for these alloys, which contain both atomic spin and chemical variables. They were parameterized on a set of key density functional theory (DFT) data, with the inclusion of non-collinear magnetic configurations being indispensable. Two distinct approaches, namely a knowledge-driven and a machine-learning approach have been employed for the fitting. Employing these models in atomic Monte Carlo simulations enables the prediction of magnetic and thermodynamic properties of the Fe-Mn alloys, and their coupling, as functions of temperature. This includes the decrease of Curie temperature with increasing Mn concentration, the temperature evolution of the mixing enthalpy and its correlation with the alloy magnetization. Also, going beyond the defect-free systems, we determined the binding free energy between a vacancy and a Mn atom, which is a key parameter controlling the atomic transport in Fe-Mn alloys.

References in corpus (12)

• Ab-initio calculations of exchange interactions, spin-wave stiffness constants, and Curie temperatures of Fe, Co, and Ni
• Orbital magnetism in the half-metallic Heusler alloys
• Effect of magnetic disorder and strong electron correlations on the thermodynamics of CrN
• Conceptual and practical bases for the high accuracy of machine learning interatomic potential
• Group-theoretical high-order rotational invariants for structural representations: Application to linearized machine learning interatomic potential
• Phonon softening in paramagnetic bcc Fe and relationship with pressure-induced phase transition
• Atomic diffusion in alpha-iron across the Curie point: an effcient and transferable ab-initio-based modelling approach
• The Dynamics of Magnetism in Fe-Cr Alloys with Cr Clustering
• Magnetic Cluster Expansion model for random and ordered magnetic face-centered cubic Fe-Ni-Cr alloys
• Linearized machine-learning interatomic potentials for non-magnetic elemental metals: Limitation of pairwise descriptors and trend of predictive power
• Effective interaction model for coupled magnetism and phase stability in bcc Fe-Co systems
• A first principles study of magnetism in Pd${}_3$Fe under pressure

Cited by in corpus (4)

• Theory of Cross Phenomena and Their Coefficients Beyond Onsager Theorem
• Magnetochemical effects on phase stability and vacancy formation in fcc Fe-Ni alloys
• Effects of magnetic excitations and transitions on vacancy formation: cases of fcc Fe and Ni compared to bcc Fe
• Simulation of thermodynamic properties of magnetic transition metals from an efficient tight-binding model