Hydrogen doping allows voltage control of ferrimagnetism

https://news.mit.edu/2021/ferrimagnet-control-magnets-0920

"new way to control magnets. Reversible system can flip the magnetic orientation of particles with a small voltage; could lead to faster data storage and smaller sensors... hydrogen atoms — or more precisely their nuclei, which are single protons — can penetrate deeply into the material, and this alters the balance of the magnetic orientations... If the needed voltage can be reduced and the speed improved... this new method may potentially revolutionize the field"