Abstract
It is known that the orbital disordered orthorhombic () perovskite, , undergoes a transition to the -type orbital ordered monoclinic phase at followed by a first-order transition to the -type orbital ordered orthorhombic phase () at . In contrast, using the high-angular-resolution synchrotron x-ray powder diffraction technique, we find that the -type orbital ordered phase appears at and coexists with the -type monoclinic phase down to . The coexistence of different orbital ordered states in the temperature range is discussed based on large octahedral distortion caused by smaller Y ions present at the site of the perovskite. Intriguingly, the temperature evolution of the coexistence of the - and -type orbital ordered phases and associated magnetic structures could be responsible for the temperature-induced magnetization reversal observed in the temperature interval . We also discuss that the correlation of phase coexistence and magnetization reversal is present in other systems.
1 More- Received 10 December 2016
- Revised 5 April 2017
DOI:https://doi.org/10.1103/PhysRevB.95.184107
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