Fermi Surface as the Driving Mechanism for Helical Antiferromagnetic   Ordering in Gd-Y Alloys
  The first direct experimental evidence for the Fermi surface (FS) driving the helical antiferromagnetic ordering in a gadolinium-yttrium alloy is reported. The presence of a FS sheet capable of nesting is revealed, and the nesting vector associated with the sheet is found to be in excellent agreement with the periodicity of the helical ordering. 
H.M. Fretwell, S.B. Dugdale, M.A. Alam, D.C.R. Hedley, A.   Rodriguez-Gonzalez, and S.B. Palmer