Mössbauer spectrum of ⁵⁷Fe associated with a vacancy in aluminium

Abstract

The Mössbauer spectrum of a rapidly quenched Al-0·02 at. %−⁵⁷Fe alloy hag been measured. The spectrum consists of two peaks. One corresponds to that of a solid solution of ⁵⁷Fe in Al and appears at S _T = 0·57 mm/s, while the other, at S _T = 0·24 mm/a, is inferred to be that of ⁵⁷Fe atoms associated with a vacancy. The s-electron density at the ⁵⁷Fe nucleus associated with the vacancy is larger than that at the nucleus in solid solution. From the change in the recoilless fraction with temperature, the Debye temperature is estimated to be 240 K. for ⁵⁷Fe in solid solution and 210 K for ⁵⁷Fe atoms associated with a vacancy.