Effect of thermal fluctuations on the recoil loops of SmCo5[subscript]/Fe nanocomposite system
Abstract
The correlation between the recoil loop openness and the activation volume has been studied for the SmCo5/α-Fe nanocomposite powder material prepared by mechanical alloying. The α-Fe phase content in the nanocomposite powders was adjusted by varying the amount of α-Fe addition in raw materials and the postannealing temperature after mechanical alloying. It was found that the recoil loop openness increases with increasing α-Fe phase content. More interestingly, there is a linear relation between the openness of recoil loops and the reciprocal activation volume, indicating that the recoil loops are related to thermal fluctuation. The large open area of the recoil loops for nanocomposite magnets is attributed to the fact that low anisotropy in the α-Fe phase leads to unstable magnetization under thermal fluctuation.