Exchange Interactions in Paramagnetic Amorphous and Disordered Crystalline CrN-based Systems

Abstract

We present a first principles supercell methodology for the calculation of exchange interactions of magnetic materials with arbitrary degrees of structural and chemical disorder in their high temperature paramagnetic state. It is based on a projection of the total magnetic energy of the system onto local pair clusters, allowing the interactions to vary independently as a response to their local environments. We demonstrate our method by deriving the distance dependent exchange interactions in vibrating crystalline CrN, a Ti${}_{0.5}$Cr${}_{0.5}$N solid solution as well as in amorphous CrN. Our method reveals strong local environment effects in all three systems. In the amorphous case we use the full set of exchange interactions in a search for the non-collinear magnetic ground state.

5 pages, 3 figures

References in corpus (4)

• Effect of magnetic disorder and strong electron correlations on the thermodynamics of CrN
• Evidence for a correlated insulator to antiferromagnetic metal transition in CrN
• Equation of state of paramagnetic CrN from ab initio molecular dynamics
• Theory of the ferromagnetism in TiCrN solid solutions

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