Magnetic interaction induced splitting of bands in hexagonal RMnO3 (R = Lu, Y, and Sc) compounds

In this work, calculations using non-collinear spin density functional theory were performed to study the electronic band structures for different antiferromagnetic orders in hexagonal RMnO₃ (R = Lu, Y, and Sc) compounds. These are an important class of multifunctional materials with interesting properties for various applications. By comparing the band structure of different magnetic configurations, it is observed that some of them exhibit band splitting that can be attributed to ferromagnetic interplane coupling. The energy splitting is significantly larger (331 meV) for the ScMnO₃ compound, which probably has a higher interplane magnetic interaction. In addition, we report that the spin–orbit coupling also induces a splitting of bands in some regions of the Brillouin zone for those magnetic configurations with a weak magnetic moment along the hexagonal c-axis. These findings offer an intriguing insight into the topological characteristics of hexagonal manganites’ band structure, which was previously unexplored in existing literature. This discovery opens avenues for future investigations in this field.