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用高频溅射法制备了两套[Pd/Co-Nb/Pd/Si]多层膜,分别用X射线衍射和振动样品磁强计做了结构和磁性测量。随Pd层厚度增加(或Co-Nb层厚度减少),Pd层由非晶态过渡到晶态,并观察到Pd的fcc(111)双峰结构,双峰的位置逐渐从两侧向体材料Pd的fcc(111)峰的位置靠近。双峰来源于Co-Nb层与Pb层、Pd层与Si层的晶格失配度以及靠近这两种界面的Pd原子的极化不同。样品的饱和磁化强度随Pd层增厚(或Co-Nb层增厚)从小于同样成分的Co-Nb合金体材料的饱和磁化强度值单调增大到大于体材料的值,并趋向稳定。这是由于Pd层极化效应、Co-Nb层维度效应及界面原子扩散效应的影响。非晶Co-Nb层能在离界面2.5nm的范围内影响Pd层的极化,这样大的极化深度与较强的界面原子扩散、Pd层较大的晶格常数变化量密切相关。
Two sets of [Pd / Co-Nb / Pd / Si] multilayers were prepared by high-frequency sputtering and their structure and magnetic properties were measured by X-ray diffraction and vibrating sample magnetometer respectively. As the thickness of Pd layer increases (or the Co-Nb layer thickness decreases), the Pd layer transitions from amorphous to crystalline and fcc (111) bimodal structure of Pd is observed. The bimodal position gradually increases from both sides to the bulk material The fcc (111) peak of Pd is in close proximity. The bimodal originates from the Co-Nb and Pb layers, the lattice mismatch between the Pd and Si layers, and the polarization of Pd atoms near these two interfaces. The saturation magnetization of the sample monotonically increases from the saturation magnetization value of the Co-Nb alloy body material with the same composition to that of the bulk material with the Pd layer thickening (or the thickening of the Co-Nb layer), and tends to be stable. This is due to the influence of the Pd layer polarization effect, the Co-Nb layer dimension effect and the interfacial atom diffusion effect. The amorphous Co-Nb layer can influence the Pd layer polarization in the range of 2.5nm from the interface, so the large polarization depth is closely related to the stronger interfacial atom diffusion and the larger lattice constant variation of the Pd layer.