Magnetoresistance effects in current‐perpendicular‐to‐plane structures based on Fe₃Si/FeSi₂ artificial lattices

Abstract

From Fe3Si/FeSi2 artificial lattices, wherein Fe3Si layers are partially epitaxially grown from the first layer on Si(111) up to the top layer across the FeSi2 layers with the same orientation relationship as that in the first layer, current‐perpendicular‐to‐plane (CPP) structures that partially contain current‐in‐to‐plane (CIP) structural portions were fabricated by a mask method. It was confirmed that the antiparallel alignment of magnetization at a zero magnetic field due to antiferromagnetic interlayer coupling is changed to parallel alignment with the applied magnetic field by polarized neutron reflectometry. The MR ratio was comparable to that of CIP structural films. It might be because a current should predominantly flow in the CIP portion since the CIP structural portion is dimensionally so large as compared with that of the CPP portion. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Temperature-dependent magnetoresistance effects in Fe3Si/FeSi2/Fe3Si trilayered spin valve junctions

“…Recently, Fe3Si has been employed as a spin injection electrode in Co60Fe40/AlOx/Fe3Si tunnel junctions [13] and in spin injection to Si [14]. We have studied spintronics based on a Fe-Si system comprising ferromagnetic Fe3Si and semiconducting FeSi2 thus far [15,16,17,18,19,20,21,22,23,24,25,26]. The combination of Fe3Si and FeSi2 has the following merits [15,16,17,27,28]: (i) the spin injection efficiency might be higher than that in TMR junctions, because the mismatch of the electrical conductivities is less than an order of magnitude, and d electrons contribute to electrical conduction in both layers, (ii) Fe3Si can be epitaxially grown on Si(111) substrates even at room substrate temperature, which is beneficial to the coherent transportation of spin-polarized electrons, and (iii) Fe3Si is feasible for a practical use since it has a high Curie temperature of 840 K and a large saturation magnetization which is half of that of Fe.…”

Film structures of Fe/B-doped carbon/Fe3Si spin valve junctions

“…We have studied Fe-Si based artificial lattices and spin valves comprising ferromagnetic Fe3Si and semiconducting FeSi2, prepared by sputtering, thus far [25][26][27][28][29][30][31][32][33][34][35][36]. Based on the preparation techniques in our previous researches, spin valve junctions comprising ferromagnetic Fe3Si and Fe layers and B-doped UNCD/a-C:H interlayers were prepared, and they were structurally investigated by transmission electron microscopy (TEM).…”

Film structures of Fe/B-doped carbon/Fe₃Si spin valve junctions

“…We have studied Fe-Si based artificial lattices and spin valves comprising ferromagnetic Fe3Si and semiconducting FeSi2, prepared by sputtering, thus far [25][26][27][28][29][30][31][32][33][34][35][36]. Based on the preparation techniques in our previous researches, spin valve junctions comprising ferromagnetic Fe3Si and Fe layers and B-doped UNCD/a-C:H interlayers were prepared, and they were structurally investigated by transmission electron microscopy (TEM).…”