Effect of the Thickness of Cr Interlayer on the High-Frequency Characteristics of FeCoTa/Cr/FeCoTa Multilayers
The effect of non-ferromagnetic Cr interlayer on the high-frequency ferromagnetic properties (HFFMPs) was investigated by use of FeCoTa/Cr/ FeCoTa triple layered films. In conventional thought, the metal interlayer gives rise to a high eddy current loss and therefore a deteriorated HFFMP. However, it is found that HFFMPs depend on the thickness of Cr interlayer. The HFFPMs are improved by Cr-interlayer with a thickness less than 12 nm (sample C1). Comparing with the Cr-interlayer-free FeCoHf single layered film (sample C0), the magnetic anisotropy field of C1 dramatically increases from 185 Oe for C0 to 558 Oe for C1. As a consequence, a high ferromagnetic resonance frequency over than 3 GHz is achieved for sample C1. When the thickness of Cr-interlayer is more than 120 nm (C2), the HFFMPs are reduced due to the increase of eddy current loss and magnetic decoupling between the ferromagnetic layers.
Jinglong Bu, Pengcheng Wang, Liqun Ai, Xiaoming Sang, Yungang Li
S. D. Li et al., "Effect of the Thickness of Cr Interlayer on the High-Frequency Characteristics of FeCoTa/Cr/FeCoTa Multilayers", Advanced Materials Research, Vols. 287-290, pp. 1356-1359, 2011