Mössbauer and structural studies of Fe_0.7-xV_xAl_0.3 alloys

We report the Mössbauer and structural studies of the alloy system Fe_0.7-xV_xM_0.3 where x = 0, 0.02, 0.06, 0.1, 0.2, and 0.3. X-ray diffraction indicates that all the samples studied have single phase with body center cubic structure. The lattice parameter (a) increases with increasing the vanadium concentration. Room temperature Mössbauer studies show magnetic ordering for small values of x and paramagnetic behavior for large values of x. The Mössbauer spectra were fitted by a distribution of magnetic hyperfine fields for small values of x and two singlets were added for large values of x. The relation between the hyperfine field and the isomer shift in the hyperfine field distribution is linear. The average hyperfine field and isomer shift were found to decrease with increasing V concentration. The results are interpreted in terms of local environmental effects on the hyperfine interactions.