DESIGN OF CERAMICS BY COTROLLING GRAIN BOUNDARY CHARACTER AND QUANTUM STRUCTURES

通过控制晶界特征和量子结构设计陶瓷

• 批准号: 14205100
• 负责人: IKUHARA Yuichi
• 金额: $ 33.53万
• 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 (A)
• 财政年份: 2002
• 资助国家: 日本
• 起止时间: 2002 至 2004
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-14205100/
• 关键词: Grain boundary character; Bicrystal; Tricrystal; Ceramics; High resolution Electron Microscopy; Dopant; Grain boundary sliding; 粒界偏析; ドーパント

The effect of grain boundary character on the properties in oxide ceramics by using bicrystals and tricrystals. The bicrystals of Al_2O_3,ZrO_2,ZnO and SrTiO_3 have systematically fabricated, and the grain boundary atomic structures, chemical bonding state and composition were characterized by HREM, EELS and EDS. In addition, the grain boundary energy, creep behavior and electronic properties in the respective bicrystals were measured, and the relationships of grain boundary structures, chemistry and properties were clarified from the view point of grain boundary character. The grain boundary structures in the respective bicrystals were thus analyzed by combination of HREM and static lattice calculation. HRTEM observation revealed that the present grain boundaries have asymmetrical structures with translation along the grain boundary plane. The most stable grain boundary models calculated by static lattice calculation well correspond with the HREM image. It was found that characters of … More grain boundary plane are an important factor to determine grain boundary atomic structures. The behavior of grain boundary sliding was also investigated by high temperature compressive creep test. The creep behavior due to grain boundary sliding was found to depend on the grain boundary structures and atomic density The [0001] tilt grain boundaries in pure alumina contained large open spaces along the boundary plane. The Y-doped boundary in alumina also exhibited a similar core structure, indicating that Y ions segregation did not change the grain boundary structure even at the atomic level. In addition, static lattice calculations showed that Y ions tended to be located around the open spaces at the grain boundary core. Therefore, it is thought that Y ions play a role for decreasing atomic diffusivity at the open grain boundary core even when their concentration is quite small. Based on the results mentioned above, importance of grain boundary atomic structures and characters were quantitatively understood, and an guideline to design ceramic grain boundary were proposed in this study. Less

晶界特征对双晶和三晶氧化物陶瓷性能的影响系统地制备了Al_2O_3、ZrO_2、ZnO和SrTiO_3双晶，并用HREM、EELS表征了晶界原子结构、化学键态和成分。此外，还对各个双晶中的晶界能、蠕变行为和电子特性进行了分析。通过结合 HREM 和静态晶格计算，从晶界特征的角度阐明了晶界结构、化学和性能之间的关系。晶界具有沿晶界面平移的不对称结构。通过静态晶格计算计算出的最稳定的晶界模型与HREM图像吻合良好。发现晶界面的特征是确定晶界的重要因素。还通过高温压缩蠕变试验研究了晶界滑动的行为，发现由于晶界滑动引起的蠕变行为取决于晶界结构和原子密度。纯氧化铝中包含的[0001]倾斜晶界。氧化铝中的Y掺杂边界也显示出类似的核心结构，这表明即使在原子水平上，Y离子偏析也没有改变晶界结构。倾向于位于晶界核心处的开放空间周围，因此，即使当它们的浓度相当小时，也认为Y离子起到降低开放晶界核心处的原子扩散率的作用。本研究定量地了解了晶界原子结构和特征的重要性，并提出了设计陶瓷晶界的指南。

项目成果

Valence state of Ti in conductive nanowires in sapphire

蓝宝石导电纳米线中 Ti 的价态

• 发表时间: 2004
• 期刊: Physical Review B 70
• 作者: M.Nakano;T.Kamo;A.Sugita;T.Handa;中村篤智 他;中村篤智 他;松永克志 他;松永克志 他;溝口照康 他
• 通讯作者: 溝口照康 他

N.Shibata, F.Oba, T.Yamamoto, Y.Ikuhara, T.Sakuma: "Atomic structure and solute segregation of a Σ=3[110]/{111} grain boundary in an yttria-stabilized cubic zirconia bicrystal"Phil.Mag.Let.. 82. 393-400 (2002)

N.Shibata、F.Oba、T.Yamamoto、Y.Ikuhara、T.Sakuma：“氧化钇稳定的立方氧化锆双晶中 Σ=3[110]/{111} 晶界的原子结构和溶质偏析”Phil .Mag.Let.. 82. 393-400 (2002)

Yuichi Ikuhara 他: "Dislocation Structures of Low-Angle and Near-Σ3 Grain Boundaries in Alumina Bicrystals"Journal of the American Ceramic Society. 86・4. 595-602 (2003)

Yuichi Ikuhara 等人：“氧化铝双晶中的低角度和近 Σ3 晶界的位错结构”，美国陶瓷学会杂志 86・4（2003 年）。

Theoretical study of defect structures in pure and titanium-doped alumina

• DOI: 10.1016/j.ssi.2004.01.044
• 发表时间: 2004-08
• 期刊: Solid State Ionics
• 影响因子: 3.2
• 作者: K. Matsunaga;A. Nakamura;Takahisa Yamamoto;Y. Ikuhara

High temperature deformation Behavior of [0001] symmetrical tilt Sigma 7 and Sigma 21 grain boundaries in alumina bicrystals

[0001] 氧化铝双晶中对称倾斜Sigma 7和Sigma 21晶界的高温变形行为

• 发表时间: 2004
• 期刊: Mater.Trans. 45
• 作者: Kazuaki MORIMOTO;Hiroshi KAWAMURA;Akinori TANI;Yuichiro YAMABE;S.Hanyu 他
• 通讯作者: S.Hanyu 他