Xinglong Ye, Harish K. Singh, Hongbin Zhang, Holger Geßwein, Mohammed Reda Chellali, Ralf Witte, Alan Molinari, Konstantin Skokov, Oliver Gutfleisch, Horst Hahn & Robert Kruk Nature Communications, 11, 4849 (2020)
Magnetic properties of micron-scale ferromagnetic metals can be modulated substantially through electrochemically-controlled insertion and extraction of hydrogen atoms in metal structure. Together with our colleagues from Karlsruhe Institute of Technology, we employed magneto-ionics technique to control the hard magnetic properties of micrometer-sized SmCo5 powder. We showed that it is possible to reversibly charge and discharge the material with hydrogen atoms by applying small voltages of only ~ 1 V. Using this approach, the coercivity of SmCo5 powder was tuned by ~1 T, that is more than two orders of magnitudes larger than previously achieved in ultrathin films by charge doping and magneto-ionics. Moreover, voltage-assisted magnetization reversal was demonstrated at room temperature. Thus, our study opens up a way to control the magnetic properties in ferromagnetic metals beyond the electric-field screening length, paving its way towards practical use in magneto-electric actuation and voltage-assisted magnetic storage.