Tuning microwave magnetic properties of composition gradient FeCoB/Ru/FeCoB trilayer films

• Published in: Journal of magnetism and magnetic materials Vol. 458; pp. 200 - 203
• Main Authors: Du, Honglei, Cao, Derang, Chu, Xian-Ming, Liu, Xiaomin, Wen, Zheng, Sun, Ruicong, Dai, Youyong, Li, Shandong, Yan, Shishen
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.07.2018; Elsevier BV
• Subjects: Anisotropy; Composition; Composition gradient sputtering; FeCoB films; Ferrites; Ferroelectrics; Ferromagnetic resonance; High frequencies; High frequency properties; Magnetic films; Magnetic properties; Magnetic resonance; Magnetism; Multilayer; Multilayered thin films; Ferromagnetic resonance; Composition gradient sputtering; Multilayer; FeCoB films; High frequency properties
• ISSN: 0304-8853; 1873-4766
• DOI: 10.1016/j.jmmm.2018.03.029

•An ultrathin Ru spacer was inserted in the middle of the 50 nm CGS FeCoB films.•The anisotropy field HK increases from 85 to 417 Oe due to inserting of Ru spacer.•FMR frequency dramatically enhanced from 4.23 to 8.36 GHz due to the Ru spacer.•Inserting Ru spacer into soft magnetic film is an effective way to enhance fr. FeCoB films were deposited by composition gradient sputtering, and an ultrathin Ru spacer was inserted in the middle of the 50 nm FeCoB films. The static and high frequency magnetic properties of the FeCoB/Ru/FeCoB trilayer films were systematically studied. The films show a good in-plane uniaxial anisotropy, and the anisotropy field increased greatly from 85 Oe to 417 Oe, while the corresponding resonance frequency was dramatically enhanced from 4.23 GHz to 8.36 GHz. Furthermore, the trilayer films also show a low damping of 0.012. This study provides a simple and effective technique to further increase the resonance frequency of soft magnetic films by inserting an ultrathin nonmagnetic spacer, which can be applied to high frequency microwave devices.