XMCD study of magnetism and valence state in iron-substituted strontium titanate
Author(s)
Tang, Astera S; Pelliciari, Jonathan; Song, Qi; Song, Qian; Ning, Shuai; Freeland, John W; Comin, Riccardo; Ross, Caroline A; ... Show more Show less
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© 2019 American Physical Society. Roomerature ferromagnetism was characterized for thin films of SrTi0.6Fe0.4O3-δ grown by pulsed laser deposition on SrTiO3 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 Fe2+ cations, whereas Fe3+ and Ti4+ did not contribute. Films with the highest magnetic moment (0.8μB per Fe) had the highest measured Fe2+:Fe3+ ratio of 0.1 corresponding to the largest concentration of oxygen vacancies (δ=0.19). 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 SrTi1-xFexO3-δ perovskite oxides and demonstrates that the magnetic moment, which correlates with the relative content of Fe2+ and Fe3+, can be controlled via the oxygen content, either during growth or by postgrowth annealing.
Date issued
2019Department
Massachusetts Institute of Technology. Department of Materials Science and Engineering; Massachusetts Institute of Technology. Department of PhysicsJournal
Physical Review Materials
Publisher
American Physical Society (APS)