Synchrotron X-ray diffraction patterns were measured and analyzed for a polycrystalline sample of the room-temperature ferromagnet Sr3.12Er0.88Co4O10.5 from 300 to 650 K, from which two structural phase transitions were found to occur successively. The higher-temperature transition at 509 K is driven by ordering of the oxygen vacancies, which is closely related to the metallic state at high temperatures. The lower-temperature transition at 360 K is of first order, at which the ferromagnetic state suddenly appears with exhibiting a jump in magnetization and resistivity. Based on the refined structure, possible spin and orbital models for the magnetic order are proposed.
@article{arxiv.0706.0605,
title = {Structure-Property Relationship in the Ordered-Perovskite- Related Oxide Sr3.12Er0.88Co4O10.5},
author = {Shintaro Ishiwata and Wataru Kobayashi and Ichiro Terasaki and Kenichi Kato and Masaki Takata},
journal= {arXiv preprint arXiv:0706.0605},
year = {2009}
}
Comments
to be published in Phys. Rev. B Rapid Communication