Magnetic structure of NicFe1-c alloys in the INVAR region has long bee
n a matter of great scientific interest and controversy. Using the loc
ally self-consistent multiple scattering method, which has recently be
en extended to treat noncollinear magnetic systems, we studied the mag
netic structure of Ni0.35Fe0.65 alloys. To simulate the alloys, we con
structed a large fcc based sample which contains 256 sites occupied ra
ndomly by Ni and Fe atoms. The ground state magnetic structure is foun
d to consist of noncollinear configurations associated with Fe-rich re
gions. In particular, Fe sites surrounded completely by other Fe atoms
have antiferromagnetic alignments, while Fe sites having less than th
ree Ni nearest-neighbors have a variety of noncollinear arrangements.
(C) 1997 American Institute of Physics.