Nanparticles of FePt were fabricated by two types of solution process. One is thermal decomposition and reduction of organometallic compounds in an organic slovent, and the other is reduction of metl ions in reversed micelles based on an aqueous solutiion process. In either way, mondisperse FePt prticles of about 3nm are fourmed. Self-assembly was observed in case of the particles fabricated by the former method, while in case of the latter method, self-assembly was not observe. The maximum diameter of particles in assembled film increased up to 10nm by annealing. Magnetic evaluation in the from of powder showed that atomic ordering of Fe and Pt in L1_0 structure strongly influenced coercivity and magnetization decay.. It is necessary to improve the accuracy for magnetic measurements of very thin assembly-films since their magnetization is too small.
