Probing the Relationship of Long-Range Order in Nanodomain FeCo Alloys with Ternary Additions Using Neutron Diffraction

The effects of tailoring FeCo alloys with addition of ternary elements Pt, Pd, Mn, Ir, and Re have been investigated. In the composition range of 30 to 70 pct Co, FeCo alloys undergo a continuous order-disorder phase transition at a maximum temperature of 730 °C at the equiatomic composition. The effects of temperature and composition on the degree of long-range order in six alloys (Fe 70 Co 30 , Fe 67 Co 30 Pt 3 , Fe 67 Co 30 Pd 3 , Fe 67 Co 30 Mn 3 , Fe 67 Co 30 Ir 3 , and Fe 67 Co 30 Re 3 ; at. pct) were compared using neutron diffraction. The transition goes along with growing of antiphase domains during the heating process.