On the structural and transport properties of the Ni-Fe invar alloy system

Several experiments concerning structural, electrical and magnetic properties of the NiFe alloy system near the composition range Fe₃Ni and temperatures ranging from 300 to 1000 K have been conducted. TEM studies using a heating stage showed transformation α→v upon heating and v→α upon cooling. Electrical resistivity measurements in the same temperature range indicate also the presence of (α+v) phase, whereas magnetic measurements in the temperature range 4,2–1000 K and fields up to 100 kOe show no indication of an ordered state.