Construction of Super-Structured Spin-Polarized Donor having Spin-rectifying Property

本计画的最终目标是建构超结构的“自旋极化供体”，作为分子自旋整流元件。本课题沿着这条路线取得了以下研究成果：1.为了提高苯并环化OF基自旋极化给体的离子自由基盐的电导率，用硒原子取代了给体部分的硫原子。还制备了这些自旋极化供体的离子自由基盐和电荷转移络合物。其中，硒引入的自旋极化供体（ESBN）的离子自由基盐被证明表现为低带隙（Ea = 40 meV）半导体，其表现出在高压下显示金属导电性的可能性。这种离子自由基盐在双交换机制的基础上通过自旋极化传导电子表现出自旋取向。2.制备了一种新型的TTF基长链给体OdTBN，以提高其在电子自旋取向方面的性能 ...更多信息 评估制造的可行性。在硅片上制备了由OdTBN组成的薄膜，发现该薄膜具有场效应晶体管（FET）的功能。3.建立了有机π自由基化学吸附Roll纳米粒子的制备方法。该纳米粒子平均粒径为4 nm，通过ca. 100分子的硫醇衍生的自旋极化供体，其通过相应的二硫化物前体的还原裂解产生。电子自旋共振谱线的极大展宽表明，金纳米粒子中化学吸附自由基的局域自旋与导电电子之间存在交换作用。此外，还与Rigaku-Denki公司合作建立了通过X射线小角散射法对金纳米粒子的精确尺寸及其分布进行评估的技术。4.合成了两端带有巯基的各种分子线，发现它们在交叉指型金电极上与金纳米粒子构成了网状结构。网络化金纳米粒子的导电性能与纳米粒子的尺寸、分子线的结构和长度密切相关。在外加磁场的作用下测量了网络结构的电导率，发现部分样品表现出磁阻效应。少

The ultimate goal of this project is to construct super-structured "spin-polarized donors" that operate as molecule-based spin-rectifying devices. The following findings along this line have been achieved during the project period.1.In order to improve the conductivity of its ionradical salt of benzo-annulated OF based spin-polarized donors, sulfur atoms of the donor moiety were replaced with selenium atoms. The ionradical salts and the charge-transfer complexes of these spin-polarized donors were also prepared. Among them, an ion-radical salt of a selenium-introduced spin-polarized donor (ESBN) turned out to behave as the low band-gap (Ea = 40 meV) semiconductor, which exhibited the possibility to show the metallic conductivity under a high pressure. Such ion-radical salts are expected to manifest spin-alignment through the spin-polarized conduction electrons on the basis of the double exchange mechanism.2.A novel TTF based donor, OdTBN, having long alkyl chains was prepared to increa … More se the feasibility of fabrication. A thin film composed of OdTBN was formed on a silicon wafer and it was found that the sample acted as a field-effect transistor (FET).3.The preparative method of Roll nano-particles chemisorbed by organic π-radical has been established. The nano-particles, with an average diameter of 4nm, were chemisorbed by ca. 100 molecules of a thiol-derivatized spin-polarized donor, which was generated by the reduction cleavage of the corresponding disulfide precursor. The extreme broadening of ESR line-shape suggests the presence of the exchange interaction between localized spins of chemisorbed radicals and conduction electrons in the gold nano-particle. Moreover, it was to be noted that the evaluation technique of the precise size and its distribution of gold nano-particles by means of an X-ray small-angle-scattering method was established in collaboration with Rigaku-Denki Corporation.4.Various molecular wires bearing thiol groups at both ends were synthesized and it was found that they constructed network-like structures with gold nano-particles on interdigitated gold electrodes. The conducting property of the networked gold nano-particles strongly depended on the size of the nano-particles and the structure and the length of molecular wires. The conductivity of the networked structures was measured under the application of an external magnetic field and it was found that some of the samples exhibited a magneto-resistance effect. Less