Line Profiles in the Nuclear Magnetic Resonance and Mössbauer Effect of TiFe1−xCox Alloys

Abstract

The ⁵⁷Fe Mössbauer effect (ME) and the ⁵⁹Co nuclear magnetic resonance (NMR) have been investigated as a function of alloy concentration, temperature, and stoichiometry in TiFe_1−xCo_x alloys over most of the range 0≤x≤1. At room temperature, in carefully prepared samples, a single ⁵⁷Fe ME line was observed for all values of x. This line broadened somewhat at low temperatures, although the magnetic properties of these alloys would have led one to expect a larger broadening at certain compositions. The ⁶⁹Co NMR linewidth was narrowest for x close to 0 or 1 and was a strong function of x as well as of temperature and magnetic field. The intermediate compositions displayed resolved satellite structures. Annealing reduced both the ME and NMR linewidths. Deviations from stoichiometry and internal oxidation were readily observable from their effect on the ME line profile. Comparisons are made with TiFe₂ and stainless steel ME spectra. Both the ME and NMR results for TiFe_1−xCo_x are consistent with a CsCl structure over the entire composition range. The NMR results indicate a lack of atomic ordering on the Co, Fe sublattice.