A New Generation of Spintronic Devices: MgO Magnetic Tunneling Junctions @ Johns Hopkins University

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We developed a low-pressure magnetron sputtering technique together with the linear dynamic deposition method and successfully fabricated a new type of magnetic tunneling junctions (MTJs) with (001) textured MgO barrier. We are the only US university to have achieved this success as of April 2007.Picture1-magnetic tunneling junctions.jpg We developed a low-pressure magnetron sputtering technique together with the linear dynamic deposition method and successfully fabricated a new type of magnetic tunneling junctions (MTJs) with (001) textured MgO barrier. We are the only US university to have achieved this success as of April 2007. Picture2-magnetic tunneling junction.jpg MgO-based MTJs exhibit magnetoresistance exceeding 200% at room temperature and low field, a major breakthrough in spintronics. The physics is coherent spin dependent tunneling, where only electron wavefuctions with certain symmetry can tunnel through. picture 3-4 tunneling 6-4-07.jpg Schematics of a MgO-based MTJ that requires modern thin film deposition and lithography. The key to our success is to minimize the interfacial roughness using low pressure sputtering. Picture5-magnetic tunneling junction.jpg We have achieved the best performance in MgO-based MTJs worldwide. Our mass production of these MTJs is used for industrial applications of metrology, magnetic sensing,Â’  and spintronic immunoassay. Download as .pdf

Related publication(s):

  1. Weifeng Shen, Dipanjan Mazumdar, Xiaojing Zou, Xiaoyong Liu, B. D. Schrag, and Gang Xiao, <strong>Effect of film roughness in MgO-based magnetic tunnel junctions</strong> , Applied Physics Letter 88, 182508 (2006).