  Novel 2D ferromagnets with high Curie temperature and large perpendicular
magnetic anisotropy are especially attractive owing to the future promising
application in modern spintronics, but meanwhile the 2D ferromagnetic materials
with high Curie temperature and large perpendicular magnetic anisotropy are
rarely reported. Based on density functional theory (DFT) calculations, we
predict a new kind of 2D ferromagnetic materials - GdB2N2, which possesses
large magnetic moment, high Curie temperature (335 K) and large perpendicular
magnetic anisotropy (10.38 meV/f.u.). Biaxial strain ranging from -0.5% to 5%
and different concentrations of charge-carrier doping are applied to reveal the
influence on the Curie temperature and magnetic anisotropy energy (MAE).
Besides, magnetic coupling process within GdB2N2 is found to be via a
Ruderman-Kittel-Kasuya-Yosida (RKKY) mechanism. In summary, our work here
predicts a novel 2D rare-earth material GdB2N2, which not only enriches the
category of 2D room-temperature ferromagnets, but also proposes a new
possibility of combining traditional 2D materials and rare-earth materials to
achieve more intriguing magnetic properties, finally it carves out the path for
the next-generation spintronic devices and sensors.
