Voltage-induced ferromagnetism in a diamagnet.

ABSTRACT: Increasingly impressive demonstrations of voltage-controlled magnetism have been achieved recently, highlighting potential for low-power data processing and storage. Magnetoionic approaches appear particularly promising, electrolytes and ionic conductors being capable of on/off control of ferromagnetism and tuning of magnetic anisotropy. A clear limitation, however, is that these devices either electrically tune a known ferromagnet or electrically induce ferromagnetism from another magnetic state, e.g., antiferromagnetic. Here, we demonstrate that ferromagnetism can be voltage-induced even from a diamagnetic (zero-spin) state suggesting that useful magnetic phases could be electrically induced in "nonmagnetic" materials. We use ionic liquid-gated diamagnetic FeS2 as a model system, showing that as little as 1 V induces a reversible insulator-metal transition by electrostatic surface inversion. Anomalous Hall measurements then reveal electrically tunable surface ferromagnetism at up to 25 K. Density functional theory-based modeling explains this in terms of Stoner ferromagnetism induced via filling of a narrow e g band.

SUBMITTER: Walter J 

PROVIDER: S-EPMC7439324 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature