The article presents results of investigation of the effect of Ag and Cu additional layers on the temperature ranges of phase transformations– formation of disordered magnetically soft $A1$-FePt phase and its subsequent transition to ordered magnetically hard $L1_{0}$-FePt phase–in nanosize Pt(10 nm)/(Ag, Cu)(x nm)/Fe(10 nm) film compositions (where x = 0, 4 nm) on SiO$_{2}$(100 nm)/Si(001) substrates during annealing in a vacuum. As determined, the introduction of Cu and Ag intermediate layers into Pt(10 nm)/Fe(10 nm) film compositions results in the decrease of the disordered and ordered phases’ formation temperatures. In addition, introduction of the additional intermediate layers causes an increase of film-materials’ coercivity after the heat treatment.