An
iron–nickel alloy or
nickel–iron alloy, abbreviated
FeNi or
NiFe, is a group of
alloys that mostly consist of the elements
nickel (Ni) and
iron (Fe). It is the main constituent of the "iron"
planetary cores and
"iron" meteorite. The acronym NiFe is used to refer to various chemical reactions that involve an iron–nickel
catalyst or component, or in geology, to refer to the general composition of
planetary cores (including
Earth's).