Fast laser annealing induced exchange bias in poly-crystalline BiFeO3/Co bilayers
Fast laser annealing induced exchange bias in poly-crystalline BiFeO3/Co bilayers
复制标题
快速激光退火引起多晶 BiFeO3/Co 双层交换偏压
DOI：
10.1016/j.apsusc.2016.01.210
复制
发表时间：
2016
影响因子：
6.7
通讯作者：
Du J.
中科院分区：
文献类型：
--
作者：
Zhang Y. Q.;Ruan X. Z.;Liu B.;Xu Z. Y.;Xu Q. Y.;Shen J. D.;Li Q.;Wang J.;You B.;Tu H. Q.;Gao Y.;Zhang W.;Xu Y. B.;Du J.
反铁磁/铁磁双层膜系统的常规场冷却工艺会严重破坏BiFeO 3（BFO）与金属铁磁层的界面，导致交换偏置（EB）的显著恶化。本文提出了一种场冷结合快速激光退火的方法，并将其应用于多晶BFO/Co双层膜，该方法可以有效地修饰EB。在有明显电子束的样品中，当激光能量密度达到某一临界值时，交换场（HE）突然增大，当激光能量密度足够大时，交换场（HE）减小。而在HE含量可忽略的样品中，适当的激光能量密度场冷后容易诱发EB。此外，HE的符号也可以改变，这取决于冷却场的方向。与此相反，通过常规热处理场冷却后，EB既不能诱导也不能增强。与传统的场冷却相比，可以通过更少的界面扩散来理解快速激光退火伴随场冷却以增强或诱导BFO/Co双层中的EB的可行性。
The conventional field cooling process for antiferromagnetic/ferromagnetic bilayer system might strongly damage the interface of BiFeO3(BFO) with metallic ferromagnetic layer, leading to significant deterioration of exchange bias (EB). In this paper, a field cooling process with fast laser annealing has been proposed and applied on polycrystalline-BFO/Co bilayers, which can effectively modify the EB. In those samples with obvious EB, it is found that the exchange field (HE) increases abruptly when the laser fluence rises to a critical value, and decreases when the laser fluence is large enough. On the other hand, in those samples with negligibleHE, EB could be easily induced after field cooling with proper laser fluence. In addition, the sign ofHEcould also be changed, depending on the direction of the cooling field. In contrast, after field cooling by conventional heat treatment, EB could be neither induced nor enhanced. The feasibility of fast laser annealing accompanied with field cooling to enhance or induce EB in the BFO/Co bilayer can be understood by much less interfacial diffusion in comparison with conventional field cooling.