Assessment of the Recoilless Fraction of Fine Goethite Particles in Mossbauer Spectroscopy

The relative recoilless fractions of goethite samples as a function of particle size were successfully determined without using the Debye approximation. The data showed that the absolute recoil-free fraction of goethite reduced with decreasing the particle size. The reduction in particle size became a cause of the particle motion that was possibly induced by a momentum transfer from incident -quanta to the goethite particles. Also, the reduction in the particle size somewhat increased the vibration frequency of the particle motion. When small goethite particles were embedded in a binder matrix, their absolute recoil-free fraction increased with decreasing the vibration frequency. It appears that the dierent properties of the binding material are possibly related to the vibration frequency of the particle motion. KCI Citation Count: 4