Electrical properties in semiconducting BaTiOィイD23ィエD2 bicrystals

半导体 BaTiOiD23iD2 双晶的电性能

• 批准号: 10450255
• 负责人: YAMAMOTO Takahisa
• 金额: $ 7.74万
• 依托单位: THE UNIVERSITY OF TOKYO
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450255/
• 关键词: BaTiOィイD23ィエD2; Bicrystal; Abnormal grain growth; Electrical properties; PTCR; I-V properties; SrTiOィイD23ィエD2; Potential Barriers; チタン酸バリウム; 半導体; ショットキーバリヤ; ポテンシャルバリヤ; 粒界構造; 結晶粒界; MREM; EELS

BaTiOィイD23ィエD2, Which is often used as based materials for electroceramics, exhibits semiconduction when it is doped with cations whose valence is large than host cations' valence. In general, most of electroceramics are utilized for practical use as in polycrystals and their electrical properties is often closely related to their grain boundary phenomena. Therefore, it must be necessary to investigate the electrical properties directly at single grain boundaries. In this study, BaTiOィイD23ィエD2 bicrystals were fabricated and then their electrical properties were examined. The following results could be obtained.(1) It was succeeded in construction of the technique for controlling the abnormal grain growth in BaTiOィイD23ィエD2 by changing A/B-site ratio. Coarse-grained structure with a grain size of about 1mm could be obtained.(2) It was found that the electrical properties in BaTiOィイD23ィエD2 bicrystal closely depend on the grain orientation relationship. The magnitude of Positive temperature coefficient of resistivity effect decerases with an increase in the coherency at grain boundaries.(3) The similar tendency could be obtained also in SrTiOィイD23ィエD2 bicrystal, which has the same lattice structure and similar electrical properties.

BaTiO_xD_23_xD_2是一种常用的电子陶瓷基料，当掺杂价态大于主体阳离子价态的阳离子时，其表现出导电性。一般来说，大多数电瓷都是以多晶体的形式用于实际应用的，它们的电性能往往与它们的晶界现象密切相关。因此，必须直接在单个晶界上研究电性能。在这项研究中，制备了BaTiOイD23 D2双晶，然后测试了它们的电学性能。可以获得以下结果。(1)成功地建立了通过改变A/B位比来控制BaTiO_（23）O_（22）O_（23）O_可以获得晶粒尺寸约为1 mm的粗晶组织。(2)发现BaTiO_xD_（23）O_xD_2双晶的电学性能与晶粒的取向关系密切相关。电阻率正温度系数效应的大小随晶界共格性的增加而减小。(3)在具有相同晶格结构和相似电学性能的SrTiO_xD_（23）O_xD_（2）双晶中也有类似的趋势。

项目成果

T.Yamamoto: "Grain Boundaries in BaTiO_3 with A Small Cation Nonstoichiometry"Key Engineering Materials. 169-170. 113-116 (1999)

T.Yamamoto：“具有小阳离子非化学计量的BaTiO_3中的晶界”关键工程材料。

T.Yamamoto, K.Hayashi, Y.Ikuhara and T.Sakuma: "Grain Boundary Structure in TiO_2-excess Barium Titanate." Journal of Materials Reserach. vol.13[12]. 3449-3452 (1998)

T.Yamamoto、K.Hayashi、Y.Ikuhara 和 T.Sakuma：“TiO_2 过量钛酸钡中的晶界结构”。

T. YAMAMOTO: "EELS Analysis for Grain Boundaries in Ti-excess BaTiO_3"Transactions of Materials Research Society of Jpn.. 24. 129-132 (1999)

T. YAMAMOTO：“EELS 分析 Ti-excess BaTiO_3 中的晶界”Transactions of Materials Research Society of Jpn.. 24. 129-132 (1999)

T. Yamamoto, K. Hayashi, Y. Ikuhara and T. Sakuma: "Chemical Bonding State at Grain Boundaries in BaTiOィイD23ィエD2 Doped with a Small Amount of Cation"Philosophical Magazine Letters. 79[6]. 327-331 (1999)

T. Yamamoto、K. Hayashi、Y. Ikuhara 和 T. Sakuma：“掺杂少量阳离子的 BaTiOiD23IeD2 晶界处的化学键合状态”哲学杂志快报 79[6]。

T. Yamamoto, Y. Ikuhara, and T. Sakuma: "EELS Analysis for Grain Boundaries in Ti-excess BaTiOィイD23ィエD2"Transactions of Materials Research Society of Japan. 24[1]. 129-132 (1999)

T. Yamamoto、Y. Ikuhara 和 T. Sakuma：“Ti 过量 BaTiOiD23D2 中的晶界的 EELS 分析”日本材料研究学会汇刊 24[1]（1999 年）。