Mossbauer effect study of lattice vibration of small iron particles

Abstract

The recoilless fraction fa has been determined as a function of temperature for small iron particles (average diameter 100 to 150 AA). The effect of the motion of the particle as a whole on the observed fa is averted by embedding the particles in matrices. The particles have an oxide surface layer 1-2 layers thick. It is concluded, from the comparison of the temperature dependences of fa for the particles and a bulk specimen, that the lattice vibration of the metallic core of the particles is not softened as compared with the bulk, while the lattice vibration of the oxide surface layer is very soft. The Debye temperature of the metallic core is found to be 470+or-30K.