[13p-2J-1~6] 10.1 Emerging materials in spintronics and magnetics (excluding semiconductors)

▼ [13p-2J-3] Spin-dependent tunneling conductance characteristics of half-metallic Co₂(Mn,Fe)Si-based magnetic tunnel junctions

〇(DC)Kidist Ayele¹, Bing Hu¹, Hongxi Liu¹, Tetsuya Uemura¹, Masafumi Yamamoto¹ (1.Hokkaido Unv.)

Keywords:Conductance spectra,Half-metallic Heusler alloys

We systematically investigated the dI/dV versus V characteristics (=G spectra) for the antiparallel magnetization alignment (AP) of magnetic tunnel junctions (MTJs) having Co₂(Mn,Fe)Si electrodes that showed giant tunneling magnetoresistance (TMR) ratios. The degree of the half-metallicity of Co₂(Mn,Fe)Si electrodes was varied by varying their film compositions. Clear dip structures were found in the G spectra for AP in a small bias region of up to ±70 mV. We found that the dI/dV value for AP at a characteristic voltage, V_s = ±70 mV, normalized by the value at V = 0 increased linearly with the TMR ratio at 4.2 K. This behavior was explained by spin-flip tunneling via magnon excited by hot electrons.