Magnetic study of the hexagonal FeMnP1-xAsx system

Abstract For the hexagonal phase FeMnP 1- x As x , neutron diffraction and Mossbauer spectroscopy results are compared. The magnetoelastic transition is accompanied by a drastic change in the 57 Fe hyperfine field that is more than twice as large in the ferro (F) than in the antiferromagnetic (AF) state. Such trends exist in FeMnX (X = As, P) and can be related to the changes in the FeFe distances.