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Researches on Transport Property and Electronic Structure of Metallic Superlattices, Metal Oxides and Metal Halogenides

金属超晶格、金属氧化物和金属卤化物的输运性质和电子结构研究

基本信息

批准号：
01460036
负责人：
TANUMA Sei-ichi
金额：
$ 3.84万
依托单位：
Iwaki Meisei University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1989
资助国家：
日本
起止时间：
1989 至 1991
项目状态：
已结题

项目摘要

(1)As one of the main research equipments for joint use in the Department of Materials Science, a MBE(molecular beam epitaxy)film growing machine was installed in 1988. The Grant was partially used for activating this MBE work, i. e., a study of metallic superlattice. Europium and strontium were chosen as the superlattice elements, because that Eu has a spin moment and Sr which is very similar to Eu in atomic size and divalency has no spin, so that interesting magnetic behaviors dependent on superlattice periods are expected. By using BaF_2 (111)face as the substrate, Sr was grown epitaxially and Eu followed. The epitaxy was proved by RHEED and X-ray diffraction. Below about 1 OK, a ferromagnetic magnetization was observed as a preliminary measurement.(2) The most important metal oxides at present should be CUO_2-based high Tc superconductors. An effective simple controlling treatment for the oxygen concentration was found in Y_1Ba_2CU_3O_y, which included a heating in the normal-atmos … More phere and a successive quenching.Researches on the conduction property of yttrium- and bismuth- oxides superconductors in the microwave frequency range were done. Different from the DC measurement, the resistance measurement iri microwave frequency range is hardly influenced by grain boundaries. It was found that the measured surface resistance showed an anomaly which related to an uncommomly large effective surface area.(3)The bromine and ICI intercalated graphite compounds were taken up as the metal halogenides, Br_2 or ICl were intercalated into KIKAFILM of Nihon Carbon Co. (an equivalent material to grafoil of the Union Carbide Co.)in the room temperature by hanging above the surface of solution of halogen and CCl_4. During the reaction term, resistance, magnetoresistance and Hall effect were in-situ measured. By analysing the obtained data, the reaction-time dependence of the concentrations of conduction holes and electrons was deduced.GaCl_3 was intercalated by co-sealing with chlorine gas and a NIKAFILM chip into a glass ampule. The first and second stage compounds were obtained at the room temperature. Higher stage compound were made by puming the ampule which included a low stage compound and heating it at the temperature of several tens ﾟC. The stage dependence of the conductivity of GaCl_3-GICs is to be investigated in order to compare to the proposed theory of the head investigator. Less

(1)As材料科学系的主要研究设备之一是分子束外延薄膜生长机，于1988年安装。该笔拨款部分用于启动这项MBE工作，即。例如，对金属超晶格的研究。选择铕和锶作为超晶格元素，因为Eu具有自旋矩，而在原子尺寸和二价态上与Eu非常相似的Sr没有自旋，因此预期有趣的磁性行为取决于超晶格周期。以BaF_2（111）面为衬底，先外延生长Sr，再外延生长Eu。通过RHEED和X射线衍射证实了外延的存在。低于约10 K，作为初步测量，观察到铁磁性磁化。(2)目前最重要的金属氧化物应该是CuO_2基高温超导体。在Y_1Ba_2Cu_3O_y中发现了一种有效的简单的氧浓度控制处理方法，即常压加热 ...更多信息研究了氧化钇和氧化铋超导体在微波频段的导电特性。与直流电阻测量不同，微波电阻测量几乎不受晶界的影响。结果发现，测得的表面电阻显示出异常，这涉及到一个不寻常的大有效表面积。（3）将溴和ICI插层石墨化合物作为金属卤化物，将Br_2或ICI插层到Nihon Carbon公司的KIKAFILM（一种与Union Carbide公司的石墨箔相当的材料）中。在室温下，将其悬挂在卤素和CCl_4溶液的表面上。在反应期间，原位测量了电阻、磁电阻和霍尔效应。通过对实验数据的分析，推导出了导电空穴和电子浓度随反应时间的变化规律。第一阶段和第二阶段化合物在室温下得到。高级化合物是通过将含有低级化合物的安瓿泵入并在几十摄氏度的温度下加热来制备的。为了与首席研究员提出的理论进行比较，将研究GaCl_3-GICs电导率的阶段依赖性。少