Epitaxial strain forms an important pathway to control the magnetic and electronic states in transition metal oxides. However, the large strain is usually accompanied with strongly suppressed oxygen vacancy formation energy, which hinders the direct manipulation of intrinsic properties particularly in strained high-valence oxide systems. Here using a post-ozone-annealing method, we obtained a series of oxygen stoichiometric SrCoO3 thin films with the tensile strain up to 3.0 observed a robust ferromagnetic ground state in all strained thin films, while interestingly the tensile strain triggers a distinct metal to insulator transition along with the increase of the tensile strain. The persistent ferromagnetic state across the electric transition therefore suggests that the magnetic state is directly correlated with the localized electrons, rather than the itinerant ones, which then calls for further investigation of the intrinsic mechanism for this magnetic compound beyond the double exchange mechanism.

中文翻译：

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高应变SrCoO3薄膜中的强铁磁性

外延应变形成了控制过渡金属氧化物中磁性和电子态的重要途径。然而，大的应变通常伴随着强烈抑制的氧空位形成能，这阻碍了直接操纵内在性质，特别是在应变的高价氧化物体系中。在这里，使用臭氧后退火方法，我们获得了一系列氧化学计量SrCoO3薄膜，其拉伸应变高达3.0，在所有应变薄膜中均观察到了坚固的铁磁基态，而有趣的是，拉伸应变触发了一种独特的金属与绝缘体随着拉伸应变的增加而转变。因此，贯穿电跃迁的持久铁磁态表明，磁态与局部电子直接相关，