%0 Journal Article
%T Chemical states of the atoms in magnetic multilayers Ta/NiO x /Ni81Fe19/Ta and Co/AlO x /Co<br>
%A Guanghua Yu
%A Fengwu Zhu
%A Chunlin Chai
%A <br>
%J 科学通报(英文版)
%D 2002
%I 
%X Ta/NiO x /Ni81Fe19/Ta and Co/AlO x /Co multilayers were prepared by rf reactive and dc magnetron sputtering. The exchange coupling field (H ex) and the coercivity (H c) of NiO x /Ni81Fe19 as a function of the ratio of Ar to O2 during the deposition process were studied. The composition and chemical states at the interface region of NiO x /NiFe were also investigated using the X-ray photoelectron spectroscopy (XPS) and peak decomposition technique. The results show that when the ratio of Ar to O2 is equal to 7 and the argon sputtering pressure is 0.57 Pa, the x value is approximately 1 and the valence of nickel is +2. At this point, NiO x is antiferromagnetic NiO and the corresponding Hex is the largest. As the ratio of Ar/O2 deviates from 7, the H ex will decrease due to the presence of magnetic impurities such as Ni+3 or metallic Ni at the interface region of NiO x /NiFe, while the H c will increase due to the metallic Ni. Al layers in Co/AlO x /Co multilayers were also studied by angle-resolved XPS. Our finding is that the bottom Co could be completely covered by depositing an Al layer about 1.8 nm. The thickness of AlO x was 1.2 nm.
%K NiO
%K x
%K /NiFe
%K exchange coupling
%K Co/AlO
%K x
%K /Co
%K X-ray photoelectron spectroscopy (XPS)
%K chemical states<br>
%U http://www.alljournals.cn/get_abstract_url.aspx?pcid=01BA20E8BA813E1908F3698710BBFEFEE816345F465FEBA5&cid=96E6E851B5104576C2DD9FC1FBCB69EF&jid=DD6615BC9D2CFCE0B6F945E8D5314523&aid=CBC0D79503052A7FC2F5BD7AB2489F7E&yid=C3ACC247184A22C1&vid=F4B561950EE1D31A&iid=E158A972A605785F&sid=44A4891E33BFF455&eid=69E4C201C13601F9&journal_id=1001-6538&journal_name=科学通报(英文版)&referenced_num=0&reference_num=10