2009 年 52 巻 11 号 p. 595-600
We investigate the magnetic structures of one-dimensional Fe nanowires grown on a Au(788) surface by x-ray magnetic circular dichroism. The long-range ferromagnetic order breaks into spin-blocks at the elevated temperature due to enhanced fluctuation in the 1D system. The average block size rapidly decreases as the temperature increases, following the Arrhenius law ruled by exchange energy and the number of antiparallel spin pairs at the boundaries. We also found a gradual change in magnetization processes depending on the coverage: from site-by-site motion of spin-block boundaries toward pinning of the boundaries at the narrow positions of the wires resulting in flips of giant spins inside the blocks.