Nd2Fe14B单晶磁畴结构随厚度的变化

观察了Nd₂Fe₁₄B单晶磁畴结构随试样厚度的变化。发现试样厚度存在某个临界值L₀,小于此值时,在垂直于e轴表面上的畴纹呈迷宫形,大于此值时,迷宫形条状畴在加宽的同时,其表面出现按一定间隔分布的斑点,此即与基畴反向的锥形畴底部,随试样厚度的进一步增加,基畴宽度和锥形反向畴尺寸也随之增大,后者的数目也增多,甚至出现多重锥形畴结构,本文着重讨论了锥形畴的形成机制,并估算了锥形畸形成所对应的临界厚度L₀。此外,根据实验结果,计算了Nd₂Fe₁₄B相的畴壁能。 关键词：

DOMAIN STRUCTURE VARIATION OF Nd2Fe14B SINGLE CRYSTAL WITH ITS THICKNESS

Domain structure variation of Nd₂Fe₁₄B single crystal with its thickness is studied. A critical thickness Lo is found, below which the maze domain pattern appears in the basal plane. When L>Lo, a set of dot-like domains appears inside the basal domains, they are the bottom of cone-shaped reversal domain. The width of basal domain and both size and number of the cone-shaped reversal domain increase with increasing sample thickness. The multiple layered reversal domains can even form with further thickness increasing. The formation of coneshaped domain is discussed, the critical thickness value for cone-shaped domain formation is estimated as well. Based on the experimental results, the domain wall energy is also calculated.