Impact of surfaces on the magnetic properties of Fe-based nanocrystalline ribbons

The properties of Fe-Co-Sn / P-B ribbons prepared by planar flow casting of the melt were investigated various methods in as-cast and nanocrystallized state. To examine the influence of surfaces on ribbon's magnetic properties was the major aim. As the surfaces and the ribbon interior possess slightly different properties, mutual macroscopic force is generated and it can affect the magnetic properties. The ribbon with P 2 at % and P-free was annealed at two different temperatures to achieve partially nanocrystalline structure. P-free ribbon shows tilted hysteresis loop after annealing, what indicates a possible surface squeeze effect. The increase of coercivity after higher temperature annealing at 380 degrees C is due to the formation of a bcc-Fe phase with a larger grain and higher crystallinity contents. Oxides, mainly Fe2O3 have been confirmed on surfaces of both the lower temperature (350 degrees C) annealed ribbons. P substitution appears to reduce the mutual force by impeding formation of crystalline phase during 350 degrees C annealing.

Automated summary

The properties of Fe-Co-Sn / P-B ribbons prepared by planar flow casting of the melt in both as-cast and nanocrystallized state were investigated. The influence of surfaces on the magnetic properties of the ribbons was examined, revealing a significant impact on magnetic properties, especially after annealing at high temperatures.