Role of Dy 4 f electrons on magnetic coupling and reorientation in DyFeO3

Abstract

Spin reorientation transition is an ubiquitous phenomenon observed in magnetic rare earth orthferrites RFeO₃, which has garnered significant attention in recent years due to its potential applications in spintronics or magnetoelectric devices. Although a plenty of experimental works suggest that the magnetic interaction between R³⁺and Fe³⁺spins is at the heart of the spin reorientation, but a direct and conclusive theoretical support has been lacking thus far, primarily due to the challenging nature of handling R 4felectrons. In this paper, we explored DyFeO₃as an example by means of comprehensive first principles calculations, and compared two different approaches, where the Dy 4felectrons were treated separately as core or valence states, aiming to elucidate the role of Dy 4felectrons, particularly in the context of the spin reorientation transition. The comparison provides a solid piece of evidence for the experimental argument that the Dy³⁺-Fe³⁺magnetic interactions play a vital role in triggering spin reorientation of Fe³⁺moments at low temperatures. The findings revealed here not only extend our understanding on the underlying mechanism for spin reorientation transition in RFeO₃, but also highlight the importance of explicit description of R 4felectrons in rationally reproducing their structural, electronic and magnetic properties.

Keywords: DyFeO3; first principles study; magnetic interaction; spin reorientation.