Epitaxial strain provides important pathways to control the magnetic and electronic states in transition metal oxides. However, the large strain is usually accompanied by a strong reduction of the oxygen vacancy formation energy, which hinders the direct manipulation of their intrinsic properties. Here using a post-deposition ozone annealing method, we obtained a series of oxygen stoichiometric SrCoO3 thin films with the tensile strain up to 3.0%. We 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 electrical 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 of this magnetic compound beyond the double-exchange mechanism.
@article{arxiv.2003.12982,
title = {Robust ferromagnetism in highly strained SrCoO3 thin films},
author = {Yujia Wang and Qing He and Wenmei Ming and Mao-Hua Du and Nianpeng Lu and Clodomiro Cafolla and Jun Fujioka and Qinghua Zhang and Ding Zhang and Shengchun Shen and Yingjie Lyu and Alpha T. N'Diaye and Elke Arenholz and Lin Gu and Cewen Nan and Yoshinori Tokura and Satoshi Okamoto and Pu Yu},
journal= {arXiv preprint arXiv:2003.12982},
year = {2020}
}