Fe基金属-酸化物グラニュラー構造薄膜の巨大磁気抵抗とHall効果 (<特集>多層膜・人工格子・グラニューラー)

概要

論文の詳細を見る
Tunnel-type giant magnetoresistance (GMR) and the Hall effect in Fe-based metal-oxide granular thin films of Fe-Mg-O and Fe-Al-O were investigated. While the magnetoresistance Δρ/ρ_o (%) of the films at RT was smaller than about 4%, it was remarkably enhanced at lower temperatures, with values of 14% for Fe_<25>Mg_<32>O_<43> and 25% for Fe_<44>Al_<17>O_<39> at 4.2 K. These MR values are comparable to or larger than that for Co-Al-O granular thin films at 4.2 K (17% at maximum). This result supports the current understanding that the magnitude of tunnel-type GMR is dependent on the spin polarization. The extraordinary Hall coefficients R_s was successfully measured in the metallic conduction region of ρ_o (μΩcm) < 10^5 for Fe-Mg-O. The R_s vs. resistivity ρ_o curve can be fitted by R_∝ρ_o^<1.0> for ρ_o<10^3, implying skew scattering. However, R_s deviates greatly below the fitting line for 10^3 < ρ_o <: 10^5 near the tunnel conduction region.
社団法人日本磁気学会の論文
1997-04-15