Enhancement of magnetic properties of Y₂C by increasing degree of localization of anionic electrons

The existence and evolution of magnetic properties of two-dimensional (2D) electride, Y₂C have been investigated using density functional theory within generalized gradient approximation. To investigate the variation of magnetic properties, a few structures with different c-axis parameters around the equilibrium value were considered. Increment of both charge and magnetization density at the interstitial site as the c-axis parameter decreases implies enhancement of the degree of localization of anionic electrons. Furthermore, the radii of the localized anionic electrons were determined from the Bader volume assigned to the interstitial sites. We observed an increase in degree of localization of anionic electrons while compressing the c-axis parameter. Exchange splitting was used to study the origin and enhancement of magnetic properties of equilibrium and deformed structures. Our calculated results confirm the main source of exchange splitting in optimized Y₂C is from anionic electrons and not from Y or C. The exchange splitting of anionic electrons increases while decreasing the c-axis parameter. Stoner-type ferromagnetic instability exists in optimized Y₂C and the Stoner parameter increases with shrinking c-values.