  Magnetism of FeRh (001) films strongly depends on film thickness and surface
terminations. While magnetic ground state of bulk FeRh is G-type
antiferromagnetism, the Rh-terminated films exhibit ferromagnetism with strong
perpendicular MCA whose energy +2.1 meV/$\Box$ is two orders of magnitude
greater than 3$d$ magnetic metals, where $\Box$ is area of two-dimensional unit
cell. While Goodenough-Kanamori-Anderson rule on the superexchange interaction
is crucial in determining the magnetic ground phases of FeRh bulk and thin
films, the magnetic phases are results of interplay and competition between
three mechanisms - the superexchange interaction, the Zener direct-interaction,
and magnetic energy gain.

Materials Science