Characteristics of Phase Transformation in Metallic Fine Particles (Martensitic transformation of Fe-Ni alloys, and ordering of CuAu and Cu3Au alloys)

Recently, much interest has been directed toward the physical properties of metallic fine particles; ferromagnetic particles of single domain and superparamagnetism are the major subjects of the magnetism. The present paper deals with characteristics of the phase transformation in fine particles as a function of particle size. Many investigations have been reported for the size effects upon the phase transformation of metal. Edwards and Lipson et al.(1)(2) observed that allotropic transformation of metallic cobalt was suppressed even at the liquid nitrogen temperature in the case of fine particles of submicron. Weil(3) found that FePt (or NiPt, CoPt) superlattices were formed very rapidly when particles of platino cyanide Pt (CN)4Fe (or Ni, Co) were reduced in hydrogen atmosphere below the critical temperature. The present author(4)(5) observed that Fe3Ni superlattice was easily formed