We have successfully calculated the electronic and structural properties of chromia (Cr2O3) in the local spin density approximation. We predict a transformation from the corundum to the Rh2O3 (II) structure around 15 GPa in the antiferromagnetic (AFM) phase as well as in the paramagnetic (PM) insulating state which occurs above the Néel temperature (TN). This transition is relevant to interpreting the optical anomalies observed in the absorption spectrum of ruby under pressure. We have modeled the structural properties of the PM state using a Landau-like expansion of the magnetostriction energy. This treatment correctly describes the structural anomalies across TN in the corundum phase and indicates that the AFM and PM insulating states should have distinct compressive behaviors.
|Original language||English (US)|
|Number of pages||4|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Nov 1 2000|