NdCeFeB快淬带相互作用与磁性能

Interaction and Magnetic Properties of NdCeFeB Melt-Spun Ribbons

摘要:

采用感应熔炼制备名义成分为(Nd_1-xCe_x)_2.4Fe₁₄B (x=0, 0.2, 0.4, 0.6, 0.8, 0.8, 1.0)的快淬带，研究了Ce取代量对快淬带的相组成、磁性能和微观结构的影响。XRD结果表明，所有快淬带均呈现四方结构(Nd, Ce)₂Fe₁₄B相，当Ce取代量超过x=0.6时，快淬带中出现CeFe₂相并且CeFe₂含量随着Ce取代量的增加而增加。快淬带的剩磁、剩磁比（M_r/M_s）和晶格常数随着Ce含量的增加而减小，当Ce取代量为x=0.2时，快淬带的磁性能为矫顽力1.31×10⁶ A/m，最大磁能积103 kJ/m³。通过小回线和δM曲线研究了快淬带的矫顽力机理和晶粒间交换耦合，在每个样品中都观察到正的δM值，证实了交换耦合相互作用的存在。Ce含量为x=0.2时δM最大值达到0.76，说明快淬带晶粒间交换耦合效应最强，这一结果与剩磁比的变化一致。SEM观察发现，Ce取代量的增加恶化快淬带的柱状晶结构。

Abstract:

The alloy ingots with nominal compositions of (Nd_1-xCe_x)_2.4Fe₁₄B (x=0, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared by induction melting and then melt-spun to form nanocrystalline ribbons. Phase composition, magnetic properties and microstructure were investigated. XRD results show that all melt-spun ribbons exhibit the tetragonal structure (Nd,Ce)₂Fe₁₄B phase. When Ce substitution content is more than x=0.6, CeFe₂ phase appears and CeFe₂ content increases with the increase in Ce substitution content. Remanence, remanence ratio (M_r/M_s) and lattice constant decrease while increasing Ce substitution content. A coercivity of 1.31×10⁶ A/m and the maximum energy product of 103 kJ/m³ for (Nd_0.8Ce_0.2)_2.4Fe₁₄B melt-spun ribbon are achieved. The coercivity mechanism and intergrain exchange coupling were studied. The positive δM value was observed in every sample, confirming the existence of exchange coupling interaction. The δM maximum value reaches 0.76 at the Ce substitution content x=0.2, indicating that the intergranular exchange coupling effect is the strongest, which is consistent with the varying remanence ratio. SEM observation reveals that increasing Ce substitution deteriorates the columnar crystal structure of ribbons.