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arXiv · 1807.09364

Giant Electrostatic Modification of Magnetism via Electrolyte-Gate-Induced Cluster Percolation in La$_{1-x}$Sr$_x$CoO$_{3-\delta}$

Jeff Walter·T. Charlton·H. Ambaye·M. R. Fitzsimmons·Peter P. Orth·R. M. Fernandes·Chris Leighton
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Abstract

Electrical control of magnetism is a long-standing goal in physics and technology, recently developed electrolyte gating techniques providing a promising route to realization. Validating a recent theoretical prediction, here we demonstrate large enhancement of electrostatic modulation of ferromagnetic order in ion-gel-gated ultrathin La$_{0.5}$Sr$_{0.5}$CoO$_{3-\delta}$ by thickness-tuning to the brink of a magnetic percolation transition. Application of only 3-4 V then drives a transition from a short-range-ordered insulator to a robust long-range ferromagnetic metal, realizing giant electrostatic Curie temperature modulation over a 150 K window. In operando polarized neutron reflectometry confirms gate-controlled ferromagnetism, also demonstrating unusually deep penetration of induced magnetization, in further agreement with theory.

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Jeff Walter, T. Charlton, H. Ambaye, M. R. Fitzsimmons, Peter P. Orth, R. M. Fernandes, Chris Leighton. 2018-07-24. Giant Electrostatic Modification of Magnetism via Electrolyte-Gate-Induced Cluster Percolation in La$_{1-x}$Sr$_x$CoO$_{3-\delta}$. https://doi.org/10.1103/physrevmaterials.2.111406

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