Effects of chemical compositions and temperatures on the distortion phenomena observed in perovskite-type structures.

化学成分和温度对钙钛矿型结构中观察到的变形现象的影响。

• 批准号: 10490009
• 负责人: HORIUCHI Hiroyuki
• 金额: $ 6.46万
• 依托单位: Hirosaki University
• 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 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-10490009/
• 关键词: perovskite; double-oxides; boride; solid solution; crystal structures; phase transition; X-ray diffraction; Rare-earth elements; 希土類オルソアルミネート; X線回析; イオン半径; 相関係; ペロブスカイト; 複酸化物; 金属間化合物; 不定比性

The relationship between chemical compositions and crystal structures were investigated through the materials surveying of perovskite-type phases. The behaviors of structural changes due to chemical compositions and temperatures were studied mainly on the double-oxide perovskite phases. On the other hand, phase stability conditions of boride perovskite phases were considered based on the boron contents as well as their physical properties such as hardness. Syntheses were performed by solid-solid reaction for double-oxides, and flux and arcmelting methods were used for the syntheses of boride perovskite phases. Crystallographic characterizations were mainly carried out by powder X-ray diffraction using shield tube source, and synchrotron radiation were applied in case of the necessity of high-resolution analyses for peak separations. The results of this research project were briefly summarized as follows :1. Double-oxide perovskite phases : Combination of trivalent rare-earth elements a … More nd Al^<3+>, that of divalent alkali-earth and tetravalent rare-earth elements as well as Zr^<4+>, were considered, and structures and structural changes of their end-member and solid solution phases were investigated. As a result, the phases of BaCeO_3, and BaPrO_3, belong to orthorhombic structures and BaZrO_3 is cubic as reported in literatures. However, BaTbO_3 is concluded to be an orthorhombic structure against the past report to be trigonal (rhombohedral lattice). Furthermore, we found that solid solutions of Ba(Pr_<1-x>, Zr_x)O_3 and Ba(Tb_<1-x>, Zr_x)O_3 show the changes from orthorhombic to cubic structures through trigonal lattice in the compositional range of x=0〜1, and that BaPrO_3 shows a similar structure change by temperature increase. These phenomena should be compared with similar structural change which takes place in the solid solution of (Sm_<1-x>, Nd_x) AlO3 by changing x and/or temperatures. Thus, the perovskite-type structures are controllable by an appropriate selection of A and B ions and a temperature condition.2. Boride perovskite : The relationship between chemical composition and structure stability of RB_<1-x>X_3 (R : Rare- earth, X : Noble metal) were mainly investigated based on the syntheses and crystallographic characterizations. The physical properties such as hardness and anti-oxidation properties were considered as well. New materials with interesting structural and physical properties are prospected by conjunction with extensive surveying of various phases, their stoichiometry and structures. Less

通过对钙钛矿型相的材料测量，研究了钙钛矿型相的化学成分与晶体结构的关系。主要研究了双氧化物钙钛矿相的化学成分和温度对结构变化的影响。另一方面，从硼含量和硬度等物理性质出发，考虑硼化物钙钛矿相的相稳定性条件。双氧化物采用固固反应合成，硼化物钙钛矿相采用助熔剂法和电弧熔炼法合成。晶体学表征主要采用屏蔽管源的粉末x射线衍射进行，在需要进行高分辨率峰分离分析时采用同步辐射。本课题的研究成果总结如下：1。双氧化物钙钛矿相：考虑了三价稀土元素a…More和Al^<3+>、二价碱土和四价稀土元素以及Zr^<4+>的组合，研究了它们的端元相和固溶体相的结构和结构变化。结果表明，BaCeO_3和BaPrO_3均为正交结构，BaZrO_3为立方结构。然而，与以往报道的三角形（菱形晶格）结构不同，BaTbO_3被认为是正交结构。此外，我们发现Ba(Pr_<1-x>, Zr_x)O_3和Ba(Tb_<1-x>, Zr_x)O_3的固溶体在x=0 ~ 1的组成范围内呈现出由正交晶格到立方晶格的结构变化，BaPrO_3的结构也随着温度的升高呈现出类似的变化。这些现象应该与（Sm_<1-x>, Nd_x） AlO3固溶体中通过改变x和/或温度而发生的类似结构变化进行比较。因此，钙钛矿型结构可以通过适当选择A和B离子和温度条件来控制。硼化物钙钛矿：主要研究了RB_<1-x>X_3 （R：稀土，X：贵金属）的合成和晶体学表征与结构稳定性的关系。同时还考虑了材料的硬度、抗氧化性能等物理性能。通过对各种相及其化学计量和结构的广泛测量，可以发现具有有趣的结构和物理性质的新材料。少

项目成果

Shigeru OKADA: "Growth condition, electrical resistivity, microhardness and thermal properties of PrRh_<4.8>B_2 single crystals synthesized from high-temperature copper solutions."Journal of the Ceramic Society of Japan. 107. 184-186 (1999)

Shigeru OKADA：“高温铜溶液合成的PrRh_<4.8>B_2单晶的生长条件、电阻率、显微硬度和热性能。”日本陶瓷学会杂志。

宍戸統悦: "不定比性ペロブスカイト型化合物ErRh_3B_χの硬さおよび耐酸化性"日本セラミックス協会学術論文誌. 108[11]. 1011-1015 (2000)

Tomietsu Shishido：“非化学计量钙钛矿化合物 ErRh_3B_χ 的硬度和抗氧化性”日本陶瓷学会杂志 108[11]（2000）。

宍戸統悦: "新しい化合物PrRh_<4.8>B_2の合成と性質"日本化学会第76回春季年会講演要旨. 3E143 (1999)

Toetsu Shishido：“新化合物 PrRh_<4.8>B_2 的合成和性能”日本化学会第 76 届春季年会摘要 3E143（1999 年）。

Shigeru Okada: "Growth conditions,electrical resistivity,micorhardness and thermal propertiees of Nb_5Sn_2Ga single crystals synthesized from high-temperature tin solutions." Journal of Alloys and Compounds. 281. 160-162 (1998)

Shigeru Okada：“高温锡溶液合成的Nb_5Sn_2Ga单晶的生长条件、电阻率、显微硬度和热性能”。

堀内弘之: "結晶組織を形成する相の微少量・微小領域での構造解析汎用システムの確立"平成9〜10年度文部省科学研究費補助金(基盤研究(B))研究成果報告書. 212 (2000)

Hiroyuki Horiuchi：“建立一个通用系统，用于对极少量和微小区域中形成晶体结构的相进行结构分析” 1997-10 文部科学省科学援助基金研究（基础研究（B））研究成果报告212（2000）。