Characterization of half-metallic L2_1-phase Co_2FeSi full-Heusler alloy films formed by rapid thermal annealing

The authors developed a preparation technique of Co_2FeSi full-Heusler alloy films with the L2_1-ordered structure on silicon-on-insulator (SOI) substrates, employing rapid thermal annealing (RTA). The Co_2FeSi full-Heusler alloy films were successfully formed by RTA-induced silicidation reaction between an ultrathin SOI (001) layer and Fe/Co layers deposited on it. The highly (110)-oriented L2_1-phase polycrystalline full-Heusler alloy films were obtained at the RTA temperature of 700 C. Crystallographic and magnetic properties of the RTA-formed full-Heusler alloy films were qualitatively the same as those of bulk full-Heusler alloy. This technique is compatible with metal source/drain formation process in advanced CMOS technology and would be applicable to the fabrication of the half-metallic source/drain of MOSFET type of spin transistors.Comment: 18 pages, 5 figure

Precipitation of amorphous ferromagnetic semiconductor phase in epitaxially grown Mn-doped Ge thin films

We investigated the origin of ferromagnetism in epitaxially grown Mn-doped Ge thin films. Using low-temperature molecular beam epitaxy, Mn-doped Ge films were successfully grown without precipitation of ferromagnetic Ge-Mn intermetallic compounds, such as Mn5Ge3. Magnetic circular dichroism measurements revealed that the epitaxially grown Mn-doped Ge films exhibited clear ferromagnetic behavior, but the Zeeman splitting observed at the critical points was not induced by the s,p-d exchange interactions. High-resolution transmission electron microscopy and energy dispersive X-ray spectroscopy analyses show phase separation of amorphous Ge1-xMnx clusters with high Mn content from a Mn-free monocrystalline Ge matrix. Since amorphous Ge1-xMnx was characterized as a homogeneous ferromagnetic semiconductor, the precipitation of the amorphous Ge1-xMnx clusters is the origin of the ferromagnetic semiconductor behavior of the epitaxially grown Mn-doped Ge films.Comment: 12pages, 4figure

Post-War Approaches to the Improvement of Pupils' "Forms of Expressions" in Making Sentences

わが国の作文・綴り方教育は,戦前には,いわゆる｢生活綴り方事件｣等によって衰退・消滅したが,戦後は,民間教育（運動）の復興を背景として,｢日本作文の会｣を中心にいち早く復興した｡しかし,1950年代初めに様々な形の｢批判｣を受け,大きく方向転換を行う｡その中で提唱されたのが,ここで取り上げる｢文章表現形体論｣である｡本稿では,この｢文章表現形体論｣の成立過程とその内容及び位置・意義等を考察することによって,わが国における戦後生活綴り方（書くこと・作文）教育史研究の一助としたい