Magnetic Properties and Microstructures of Sm-Fe-Ti Alloys With ThMn12 Structure Prepared by Melt-Spinning Method

Abstract

The effects of annealing temperature (T-a, 600 degrees C-950 degrees C) and Sm content on the phase transformation and magnetic properties of SmxFe11Ti (x = 0.9, 1.0, and 1.1) alloys prepared by the melt-spinning method were investigated. In all specimens with different compositions, the crystal structure was transformed from the TbCu7 to ThMn12 structure as T-a increased. The coercivity reached 6.3 kOe in a SmFe11Ti ribbon annealed at 850 degrees C. However, the grain size of this ribbon was much smaller than the critical single domain size of the SmFe11Ti alloy. The microstructural analysis revealed that the ribbons were highly strained. To overcome the abnormal low coercivity of SmFe11Ti alloy, precise control of the composition and removal of strain without grain growth are the critical factors.