Abstract
Room-temperature ferromagnetism was characterized for thin films of grown by pulsed laser deposition on and Si substrates under different oxygen pressures and after annealing under oxygen and vacuum conditions. X-ray magnetic circular dichroism demonstrated that the magnetization originated from cations, whereas and did not contribute. Films with the highest magnetic moment ( per Fe) had the highest measured : ratio of 0.1 corresponding to the largest concentration of oxygen vacancies . Postgrowth annealing treatments under oxidizing and reducing conditions demonstrated quenching and partial recovery of magnetism respectively, and a change in Fe valence states. The study elucidates the microscopic origin of magnetism in highly Fe-substituted perovskite oxides and demonstrates that the magnetic moment, which correlates with the relative content of and , can be controlled via the oxygen content, either during growth or by postgrowth annealing.
- Received 8 November 2018
- Revised 19 February 2019
DOI:https://doi.org/10.1103/PhysRevMaterials.3.054408
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