posted on 2021-12-28, 18:06authored byLei Zhang, Cheng Tang, Stefano Sanvito, Yuantong Gu, Aijun Du
Electrically controlled magnetism
in two-dimensional (2D) multiferroics
is highly desirable for both fundamental research and the future development
of low-power nanodevices. Herein, inspired by the recently experimentally
realized 2D antiferromagnetic MnPSe3 [Nat. Nanotechnol. 2021, 16 (7), 782] and guided by a heteromagnetic structural design, we engineer strong
magnetoelectric coupling in a hydrogen-intercalated 2D MnPSe3 bilayer. Hydrogen functionalization breaks the centrosymmetry of
bilayer MnPSe3, leading to out-of-plane ferroelectricity.
Moreover, there is a phase transition from antiferromagnetic semiconductor
to ferromagnetic half-metal in the H-bonded MnPSe3 layer,
while the other remains antiferromagnetic and semiconducting. When
reversing the electrical polarization, the intercalated H atom can
flip between the top and bottom layers with an ultralow switching
barrier, which allows one to tune the magnetic order and conductivity
of the individual layers via an external electric field. Our results
pave a new avenue to realize strong magnetoelectric coupling in single-phase
multiferroic material. The ferroelectricity-controlled magnetic phase
transition and half-metallicity offer promising applications in nanoscale
spintronics such as electrically written and magnetically read memories.