Abstract
The perovskite ruthenates (, 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 achieved via Ba substitution ( with ). An initial Ba substitution to not only changes the ferromagnetic properties, but also tunes the perpendicular magnetic anisotropy via flattening the Ru–O–Ru bond angle (to ), resulting in the maximum Curie temperature and an extinction of rotational distortions at . For , the reduction of octahedral rotational distortion dominantly enhances the ferromagnetism in the system, though competing with the effect of the tetragonal distortion. Further increasing Ba substitution gradually enhances the tetragonal-type distortion, resulting in the tuning of orbital occupancy and suppression of ferromagnetism. Our results demonstrate that isovalent substitution of the cations significantly and controllably impacts both electronic and magnetic properties of perovskite oxides.
3 More- Received 28 November 2022
- Revised 29 January 2023
- Accepted 17 March 2023
DOI:https://doi.org/10.1103/PhysRevB.107.144405
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