The essential role of magnetic frustration in the phase diagrams of doped cobaltites

Peter P. Orth; Daniel Phelan; J. Zhao; H. Zheng; J. F. Mitchell; C. Leighton; Rafael M. Fernandes

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arXiv · 2105.06402

The essential role of magnetic frustration in the phase diagrams of doped cobaltites

Peter P. Orth·Daniel Phelan·J. Zhao·H. Zheng·J. F. Mitchell·C. Leighton·Rafael M. Fernandes

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Abstract

Doped perovskite cobaltites (e.g., La$_{1-x}$Sr$_x$CoO$_3$) have been extensively studied for their spin-state physics, electronic inhomogeneity, and insulator-metal transitions. Ferromagnetically-interacting spin-state polarons emerge at low $x$ in the phase diagram of these compounds, eventually yielding long-range ferromagnetism. The onset of long-range ferromagnetism ($x \approx 0.18$) is substantially delayed relative to polaron percolation ($x \approx 0.05$), however, generating a troubling inconsistency. Here, Monte-Carlo simulations of a disordered classical spin model are used to establish that previously ignored magnetic frustration is responsible for this effect, enabling faithful reproduction of the magnetic phase diagram.

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Peter P. Orth, Daniel Phelan, J. Zhao, H. Zheng, J. F. Mitchell, C. Leighton, Rafael M. Fernandes. 2021-05-13. The essential role of magnetic frustration in the phase diagrams of doped cobaltites. https://arxiv.org/abs/2105.06402

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