The 205th Special MMU seminar   


Spin torque oscillators using Co-based Heusler alloys

Prof. Takeshi Seki
Institute for Materials Research, Tohoku University

Date & Time: 15:30 - 16:30, June 12th (Fri), 2015.
Place: 7F Small Seminar Room, Sengen

Abstract:

  A spin torque oscillator, which is a nanometer-sized rf oscillator, has several issues needing to be solved simultaneously for practical applications: the enhancement in rf output power, narrowing the oscillation linewidth, and the improvement of frequency controllability. In this talk, spin torque oscillators with Co-based Heusler alloys are introduced and their advantages are discussed. Owing to the high spin-polarization of Co2(Fe0.4Mn0.6)Si, we successfully enhanced the rf output power even in the case of all-metallic multilayered stack. Also, we optimized the device structure in order to control the excited magnetization dynamics in the Heusler alloy layer. We found that the narrow oscillation linewidth together with the increased rf output power was achieved by exploiting the vortex-like oscillation mode.