Magnetic Materials group (Prof. Takanashi’s group) has found, in collaboration with Prof. S. Imada, Osaka University, the thinnest limit for the perpendicular magnetization in FePt thin films at room temperature, using soft x-ray magnetic circular dichroism measurements in SPring-8/JASRI. FePt films keep perpendicular magnetization at room temperature even for the thickness down to 1 nm, but only at low temperature for the thicknesses smaller than 1 nm. FePt ordered alloy with large magnetic anisotropy, guaranteeing the thermal stability of magnetization on a nanometer scale, has attracted much attention for the application to ultra-high density magnetic storage devices. The understanding of the thinnest limit is important from a practical point of view. This result was published in Applied Physics Letters, and also introduced in Nikkan-Kogyo Shimbun (March 16) and Nikkei-Sangyo Shimbun (March 19).
The thinnest limit of room-temperature perpendicular magnetization in FePt films