Structural and Mössbauer spectroscopic studies of Fe0.7−xCrxAl0.3 alloys

Abstract Fe 0.7− x Cr x Al 0.3 alloys with x =0, 0.1, 0.2, 0.3 and 0.35 have been synthesized by arc melting and studied by X-ray diffraction and Mossbauer spectroscopy. All the samples studied were found to have single phase with body center cubic structure. The lattice parameter a , and hence the volume, were obtained from the X-ray diffraction patern and found to increase with increasing the chromium concentration. At room temperature Mossbauer studies show magnetic ordering for small values of x and paramagnetic behavior for large values of x under investigation. The Mossbauer spectra were analyzed considering a distribution of magnetic hyperfine fields for small values of x and two singlets were added for large values of x . During the fitting procedure, the relation between the hyperfine field and the isomer shift in the hyperfine field distribution was linear relation. The average hyperfine field and isomer shift as a function of chromium content x were found to decrease with increasing x . The results are explained in terms of local environmental effects on the hyperfine interactions.