Mössbauer-effect study of local atomic order in bcc Fe100−xTix alloys with x ≤ 12

Fe100−xTix alloys with x ≤ 12 were investigated by means of 57Fe Mössbauer spectroscopy (MS) and scanning electron microscopy (SEM) with respect to the distribution of Ti atoms in the iron matrix. MS measurements which were carried out at 80 and 295 K gave a clear evidence that the distribution is not homogenous, i.e. it cannot be described in terms of the binomial distribution. The number of Ti atoms within the first two neighbour shells was found to be greater than the one expected for the random distribution indicating a clustering effect. It was further revealed that Ti atoms occupy the first neighbour shell nearly randomly, while their occupancy in the second neighbour shell is more frequent than the one expected from the binomial distribution. Quantitatively, the effects were described in terms of the SRO-order parameters. SEM study revealed the existence of precipitates of TiFe2 compound as well as FeTi2 one.