Controlling Magnetic Properties in Bulk Ferromagnetic Metals By Electrochemical Charging and Discharging of Hydrogen Atoms

• Published in: Meeting abstracts (Electrochemical Society) Vol. MA2019-02; no. 51; p. 2259
• Main Authors: Ye, Xinglong, Kruk, Robert, Hahn, Horst
• Format: Journal Article
• Language: English
• Published: 01.09.2019
• ISSN: 2151-2043; 2151-2035
• DOI: 10.1149/MA2019-02/51/2259

Controlling magnetic properties of materials with external voltages has attracted much interest owing to its promising applications in various areas like actuation. However, the voltage effect in metals is usually restricted to few atomic layers as well as too small for real use due to strong electric field screening. Here, for the first time, we show that bulk magnetic properties of ferromagnetic metal can be tuned significantly through charging and discharging of hydrogen atoms. We manipulated the coercivity of micrometer-sized SmCo5 grains by a fraction of tesla with a voltage of only around 1 V. Employing this approach, voltage-assisted magnetization reversal is realized at room temperature. Through both experiments and simulation, we found that the huge voltage effect originates from the significant change of magnetocrystaline anisotropy in surface regions of SmCo5 grains due to hydrogen insertion and removal, which modifies the nucleation field during magnetization reversal. This work opens up a route for overcoming the screening length and has implication, for example, for using SmCo5 in sensors and actuators.