Abstract: Based upon micromagnetics and variational method of the total free energy of the magnets, we derived Brown equation of the magnetization for the aligned nanom-eterscale two-phase exchange-coupling permanent. For the case of the aligned two-phase exchange-coupling permanent, this Brown equation is similar to static Schrdinger equation. By means of the method of resolving the central-field problem, we obtained the dependence of the nucleation fields of the two-phase exchange-coupling permanents vary with the particle sizes of hard magnet phase. It's shown that the excellent magnetic properties of permanents are obtained when the sizes of the twophase crystals are smaller than the critical sizes, respectively. The present calculation results can be used to explain the known experimental results and provide the theoretical reference for the preparing of the giant-magnetic energy product permanents.

Key words: magnetic nanomaterial, exchange-coupling permanent, magnetic properties, micromagnetics