摘要
Controlling oxygen redox reactions in transition metal oxides offers an attractive route to tune their physical properties;a topotactic structural transformation from their parent phases effectively modifies the electronic state. In this work, infinitelayered SrFeO_(2) thin films were produced from brownmillerite SrFeO_(2.5) via low-temperature hydro-reduction. After the structural transition, their out-of-plane lattice constants dramatically shrank by 12%;tensilely strained samples exhibited metallic character, whereas the compressively strained ones maintained the insulating behavior of their bulk form. According to X-ray linear dichroism results, this strain-mediated electronic anisotropy may be attributed to electron redistribution within degenerated orbitals. This suggests a possible mechanism for the metallic conductivity of infinite-layered SrFeO_(2), giving a hint for understanding emergent quantum phenomena, such as the recently discovered superconductivity in nickelates, and stimulating various applications, including in ionic conductivity and oxygen catalysis.
基金
supported by the National Key Basic Research Program of China(Grant Nos.2020YFA0309100,and 2019YFA0308500)
the Program for the Innovation Team of Science and Technology in University of Henan(Grant No.20IRTSTHN014)
the Excellent Youth Foundation of He’nan Scientific Committee(Grant No.202300410356)
the National Natural Science Foundation of China(Grant No.11974390)
the Beijing Nova Program of Science and Technology(Grant No.Z191100001119112)
the Beijing Natural Science Foundation(Grant No.2202060)
the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB33030200)。
