Impact of a magnetic field on grain boundary energy in 99.9% iron and iron-tin alloy

We have investigated the effect of a magnetic field on grain boundary energy in a 99.9% Fe and an Fe-0.8at.%Sn alloy. The average grain boundary energy in the Fe-Sn alloy was increased by application of a magnetic field. The energy curves as a function of misorientation angle showed cusps at the angles corresponding to CSL relations irrespective of whether a magnetic field was applied. The misorientation dependence of grain boundary energy was more observable after magnetic annealing, probably because of a decrease in Sn segregation to grain boundaries due to a magnetic field. Temperature-dependence of grain boundary energy in 99.9% Fe was measured. The grain boundary energy increased linearly with increasing temperature without a magnetic field, while it decreased with a 6 T magnetic field. The difference in temperature coefficient of grain boundary energy observed would come from the magnetic-field effect on the impurity segregation. Furthermore a discontinuity of temperature dependence of grain boundary energy was found at the Curie temperature under a 6 T magnetic field.