Coexistence of G- and C-type orbital ordered phases and its correlation with magnetization reversal in YVO3
Résumé
It is known that the orbital disordered orthorhombic (Pnma) perovskite, YVO3, undergoes a transition to the G-type orbital ordered monoclinic phase (P112(1)/a) at TG-OO similar to 200 K followed by a first-order transition to the C-type orbital ordered orthorhombic phase (Pnma) at T-S similar to 77 K. In contrast, using the high-angular-resolution synchrotron x-ray powder diffraction technique, we find that the C-type orbital ordered phase appears at T-N = 116 K and coexists with the G-type monoclinic phase down to TS similar to 77 K. The coexistence of different orbital ordered states in the temperature range T-S < T < T-N is discussed based on large octahedral distortion caused by smaller Y ions present at the A site of the perovskite. Intriguingly, the temperature evolution of the coexistence of the G- and C-type orbital ordered phases and associated magnetic structures could be responsible for the temperature-induced magnetization reversal observed in the temperature interval T-S < T < T-N. We also discuss that the correlation of phase coexistence and magnetization reversal is present in other RVO3 systems.