Abstract
The perovskite ruthenates (ARuO3, A=Ca, Ba, or Sr) exhibit unique properties owing to a subtle interplay of crystal structure and electronic-spin degrees of freedom. Here, we demonstrate an intriguing continuous tuning of crystal symmetry from orthorhombic to tetragonal (no octahedral rotations) phases in epitaxial SrRuO3 achieved via Ba substitution (Sr1-xBaxRuO3 with 0≤x≤0.7). An initial Ba substitution to SrRuO3 not only changes the ferromagnetic properties, but also tunes the perpendicular magnetic anisotropy via flattening the Ru-O-Ru bond angle (to 180°), resulting in the maximum Curie temperature and an extinction of RuO6 rotational distortions at x≈0.20. For x≤0.2, the reduction of RuO6 octahedral rotational distortion dominantly enhances the ferromagnetism in the system, though competing with the effect of the RuO6 tetragonal distortion. Further increasing Ba substitution (x>0.2) gradually enhances the tetragonal-type distortion, resulting in the tuning of Ru-4d orbital occupancy and suppression of ferromagnetism. Our results demonstrate that isovalent substitution of the A-site cations significantly and controllably impacts both electronic and magnetic properties of perovskite oxides.
| Original language | English |
|---|---|
| Article number | 144405 |
| Journal | Physical Review B |
| Volume | 107 |
| Issue number | 14 |
| DOIs | |
| State | Published - Apr 1 2023 |
Funding
This work is primarily supported by the U.S. Department of Energy (DOE) under Grant No. DOE DE-SC0002136. The electron microscopy work done at Brookhaven National Laboratory (BNL) was sponsored by the U.S. DOE-BES, Materials Sciences and Engineering Division, under Contract No. DE-SC0012704. Use of the BNL Center for Functional Nanomaterials supported by the BES Office of User Science Facilities for TEM sample preparation is also acknowledged. Work at Oak Ridge National Laboratory was supported by the U.S. DOE, Office of Basic Energy Sciences (BES), Materials Sciences and Engineering Division. The work at Los Alamos National Laboratory was supported by the NNSA's Laboratory Directed Research and Development Program, and was performed, in part, at the CINT, an Office of Science User Facility operated for the U.S. Department of Energy Office of Science through the Los Alamos National Laboratory. Los Alamos National Laboratory is operated by Triad National Security, LLC, for the National Nuclear Security Administration of U.S. Department of Energy (Contract No. 89233218CNA000001).