Figure 1

(Color online) Phonon dispersions of the rhombohedral MnO and NiO, expressed using the symmetry of the cubic structure. The calculated phonon dispersions by this work with TO splitting along the $\Gamma \text{-X}$ and $\Gamma \text{-L}$ directions due to symmetry breaking are represented by the dot-dashed (blue) curves, and the calculated phonon dispersions by this work without splitting are represented by solid (black) curves. (a) MnO: the crosses, the filled circles, and the open (blue) squares represent the measured data by Haywood and Collins (Ref. 6), Wagner et al. (Ref. 8), and Chung et al. (Ref. 4), respectively; the dashed (red) curves are from the calculations by Wdowik and Legut (Ref. 15); and (b) NiO: the crosses and the circles represent the measured data by Coy et al. (Ref. 15) and Reichardt et al. (Ref. 7), respectively; the dashed (red) curves are from the DMFT calculations by Savrasov and Kotliar. (Ref. 14)Reuse & Permissions

Figure 2

Calculated specific heats (solid curves) of (a) MnO and (b) NiO in comparison with the experimental data (open circles) for MnO by Shapiro et al. (Ref, 36) and NiO by Seltz et al. (Ref. 35).Reuse & Permissions