Formation of tree-like and vortex magnetic domains of nanocrystalline a-(Fe,Si) in La-Fe-Si ribbons during rapid solidification and subsequent annealing
Formation of tree-like and vortex magnetic domains of nanocrystalline a-(Fe,Si) in La-Fe-Si ribbons during rapid solidification and subsequent annealing
复制标题
La-Fe-Si带材在快速凝固和后续退火过程中形成树状和涡旋磁畴的纳米晶a-(Fe,Si)
DOI：
10.1016/j.jallcom.2016.01.211
复制
发表时间：
2016
期刊：
影响因子：
--
通讯作者：
Manh-Huong Phan
中科院分区：
文献类型：
--
作者：
Xueling Hou;Yue Tian;Yun Xue;Chunyu Liu;Weixing Xia;Hui Xu;Paula Lampen-Kelley;Hariharan Srikanth;Manh-Huong Phan
利用室温洛仑兹力显微镜和电子全息术研究了不同热处理条件下快淬La-Fe-Si薄带表面的特征磁畴。在作为淬火带，磁畴结构被发现从一个树枝状形态的表面上远离铜轮在淬火过程中与车轮接触的表面上的涡旋型畴结构的变化。在退火的初始阶段，在两个表面上的域开发的涡旋行为。详细的显微组织观察表明，由于α-（Fe，Si）与LaFeSi之间的包析反应部分完成，α-（Fe，Si）纳米晶区域嵌入了La（Fe，Si）13相中。室温下的磁畴随着热处理时间的延长而沿着消失，同时残留的α-（Fe，Si）相也随之消失，得到了均匀的La（Fe，Si）13材料。磁性测量和分析表明，α-（Fe，Si）和La（Fe，Si）13相之间没有强耦合，因此具有涡旋型结构的α-（Fe，Si）纳米晶的存在不利于带中磁热响应的增强。
The characteristic magnetic domains at the surfaces of melt-spun La–Fe–Si ribbons under different thermal processing conditions are explored using room-temperature Lorentz force microscopy and electron holography. In as-quenched ribbons, the magnetic domain structure is found to change from a tree-like morphology on the surface far from the copper wheel during quenching to a vortex-type domain structure on the surface in contact with the wheel. In the initial stages of annealing, domains on both surfaces developed a vortex behavior. Detailed microstructural observations demonstrated nanocrystallineα-(Fe,Si) regions embedded in the majority La(Fe,Si)13phase due to a partially completed peritectoid reaction betweenα-(Fe,Si) and LaFeSi. The room temperature magnetic domains disappeared along with the residualα-(Fe,Si) upon extended heat treatment, yielding a homogeneous La(Fe,Si)13material. Magnetometry measurements and analysis reveal the absence of strong coupling between theα-(Fe,Si) and La(Fe,Si)13phases, so that the presence ofα-(Fe,Si) nanocrystallites with a vortex-type structure does not favor an enhanced magnetocaloric response in the ribbons.