Magnetic properties of FeNi alloys for high-temperature thermomagnetic power generation.

In this paper, the magnetic properties and heat transfer performance of Fe99.3-xNixMn0.4Si0.3 (x=33,35,37,39,41,43) alloys near the Curie temperature(Tc) were investigated. The results show that the Fe99.3-xNixMn0.4Si0.3 alloys have a wide Curie-temperature window and their Tc approximately linearly increases from 450K to 647K with the Ni content increasing from 33% to 43%. The change rate of the magnetic induction(ΔB•ΔT-1) near the Curie temperature shows the peak with changing the temperature. The ΔB•ΔT-1 of Fe99.3-xNixMn0.4Si0.3 (x≥37) alloys is higher than the reported maximum of 0.0202T•K-1 for second-order phase transition materials. Therefore, the Fe100-xNixMn0.4Si0.3 alloys are suitable for thermomagnetic power generation in the temperature range above 473K. The energy conversion process of a platy sample (0.2×0.2×0.001m3) of the alloy with x=37 in the static thermomagnetic power generation was simulated and the maximum electromotive force of 1.47V was generated in the simulation.