[13p-PA1-1~33] 10 Spintronics and Magnetics（Poster）

▲ [13p-PA1-14] Transport properties in tunnel junction with IrMn ultrathin film

〇Minori Goto¹, Shinji Miwa¹, Kohei Nawaoka¹, Shohei Hatanaka¹, Norikazu Mizuochi¹, Yoshishige Suzuki¹ (1.Osaka Univ.)

Keywords:antiferromagnet,ultrathin film,tunneling anisotropic magnetoresistance

Ultrathin film of 3d magnetic metal attracts a great attention in spintronics, since its magnetic properties can be controlled by voltage [1-3]. To investigate this, it is important to understand the magnetic properties, such as a magnetic anisotropy and a transition temperature because the magnetic properties in ultrathin films are different from that of bulk. Previously, there have been many investigations in ferromagnetic ultrathin films [1-3]. However, an antiferromagnetic ultrathin film has not been investigated due to the difficulty of experiments. In this study, we attempted to investigate the magnetic properties in antiferromagnetic ultrathin IrMn films by characterizing the tunneling anisotropic magnetoresistance in IrMn/MgO tunnel junctions [4].
The IrMn/MgO tunnel junction with a diameter of 5 mm was fabricated by magnetron sputtering, photo-lithography and Ar ion milling. The resistance was measured between the top and bottom electrode. We measured the voltage dependence of the resistance. The local maximum was observed at V = 0, which indicates the tunnel transport. We will discuss the magnetotransport properties of ultrathin IrMn film from a temperature and magnetic field dependence of the device resistance.
This work was supported by ImPACT Program of Council for Science, Technology and Innovation.
[1] M. Weisheit, et. al., Science, 315, 349 (2007)
[2] T. Maruyama, et. al., Nat. Nanotech, 4 158 (2009)
[3] D. Chiba, et. al., Nat. Matter, 10, 853 (2011)
[4] B. G. Park, et. al., Nat. Matter, 10 347 (2011)