  We propose that stable two-dimensional (2D) ferromagnets can be made of
regular single-layered lattices of single-molecule nanomagnets with enough
uniaxial magnetic anisotropy on appropriate substrates by controlling the
inter-nanomagnet magnetic interaction. Our Monte Carlo simulated results show
that such ideal 2D ferromagnets are thermodynamically stable when the
anisotropy is strong enough. If the anisotropy energy equals 80 K,
approximately that of the Mn12, the T_c varies from zero to 15 K depending on
different inter-nanomagnet coupling constants. Such stable spin systems,
experimentally accessible, should be promising for information applications.
