Corrosion behavior and ΔS-Tc relation of LaFe13−x−yCoxSiyCz compounds near room temperature

Corrosion behavior and ΔS-Tc relation of LaFe13−x−yCoxSiyCz compounds near room temperature have been investigated. The ΔS-Tc relation shows that element doping of Si, Co and C shifts Tc to high temperature, but decreases the ΔS value. Si doping has the largest effect on ΔS value decrease. The rapid decrease in ΔS value is associated with a significant decrease of saturation magnetic moment. While taking high Si content, Co doping decreases ΔS value more slowly. On the other hand, introducing interstitial C atoms only decreases ΔS slightly with increasing Tc to high temperature. Both replacing Fe with Co and adding C can improve the corrosion resistance, but adding C has more prominent effect. Therefore introducing interstitial C atoms makes it possible to adjust Tc to high temperature, while still keeping ΔS at a large value and increasing the corrosion resistance.