Abstract A single layer of CoFeB and a multilayer of CoFeB--MgO films are prepared by means of DC/RF magnetron sputter deposition. The excellent microwave properties and high electrical resistivity are simultaneously achieved in the discontinuous multilayer structure of [Co$_{44}$Fe$_{44}$B$_{12}$(0.7 nm)/MgO(0.4 nm)]$_{40}$ film. This film has a high permeability ($\mu \prime $) (larger than 100 below 2.1 GHz), a high magnetic loss ($\mu''$) (larger than 100 in a range from 1.5 to 3.3 GHz), a resistivity of 3.3$\times 10^{3}\mu \Omega \cdot$ cm, a saturation magnetization of 1.2 T, and an in-plane uniaxial anisotropy field of 5.5 kA/m. The microstructure and the surface topography of the film are also analysed. The relatively large surface roughness for the discontinuous film is responsible for the wide frequency band of magnetic loss. The magnetic loss and the high resistivity indicate that the discontinuous CoFeB--MgO multilayer film has potential applications in microwave absorbers and electromagnetic interference (EMI) shielding materials in a GHz frequency range.
Received: 11 October 2008
Revised: 31 October 2008
Accepted manuscript online:
PACS:
75.70.Cn
(Magnetic properties of interfaces (multilayers, superlattices, heterostructures))
Fund: Project supported by the National
Natural Science Foundation of China (Grant Nos 50371029 and
50771047), the Program for the New Century Excellent Talents in
University of the Ministry of Education, China (Grant No
NCET20420702), and the Natural Science F
Cite this article:
Ma Qiang(马强), Jiang Jian-Jun(江建军), Bie Shao-Wei(别少伟), Tian Bin(田斌), Liang Pei(梁培), and He Hua-Hui(何华辉) Microwave properties and surface topography of soft magnetic films with high resistivity 2009 Chin. Phys. B 18 2063
Different behavior of upper critical field in Fe1-xSe single crystals Shunli Ni(倪顺利), Wei Hu(胡卫), Peipei Shen(沈沛沛), Zhongxu Wei(魏忠旭), Shaobo Liu(刘少博), Dong Li(李栋), Jie Yuan(袁洁), Li Yu(俞理), Kui Jin(金魁), Fang Zhou(周放), Xiaoli Dong(董晓莉), Zhongxian Zhao(赵忠贤). Chin. Phys. B, 2019, 28(12): 127401.
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