Structural and Mossbauer spectroscopic studies of Fe0.7-xCrxAl0.3 alloys

Fe-0.7 (-) xCrxAl0.3 allows with x=0, 0.1, 0.2, 0.3 and 0.35 have been synt hesized by are melting and studied by X-ray diffraction and Mossbauer spect roscopy. 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 incr easing the chromium concentration. At room temperature Mossbauer studies sh ow magnetic ordering for small values of x and paramagnetic behavior for la rge values of x under investigation. The Mossbauer spectra were analyzed co nsidering a distribution of magnetic hyperfine fields for small values of x and two singlets were added for large values of x. During the fitting proc edure, the relation between the hyperfine field and the isomer shift in the hyperfine field distribution was linear relation. The average hyperfine fi eld and isomer shift as a function of chromium content x were found to decr ease with increasing x. The results are explained in terms of local environ mental effects on the hyperfine interactions. (C) 2001 Elsevier Science B.V . All rights reserved.