On the possibility of magnetic ordering (T-C(N)) induced by a surface exchange interaction in an Ising nanoparticle with T-C(N) > T-C(B), where TC(B) is a transition temperature in the corresponding bulk system

摘要

The phase transitions of two nanoparticles and their corresponding bulk systems are examined by the effective-field theory with correlations. It is clarified that the transition temperatures of such small nanoparticles may become larger than those of its corresponding bulk systems, when the surface exchange interaction is selected as a large value.