Decorated Ising nanoparticles with high critical temperature

The phase transitions of two magnetic nanoparticles and their decorated nanoparticles are examined by the effective-field theory with correlations. They are consisted of two isolated paramagnetic Ising nanoparticles coupled by an exchange interaction. It is discussed whether a ferromagnetic nanoparticle with a transition temperature T-C(N) larger than that (T-C(B)) of a bulk ferromagnetic material is possible.