Synthesis, single crystal structure and lattice parameters

合成、单晶结构和晶格参数

• 批准号: 310625331
• 负责人: Professor Dr. Jens Götze
• 金额: --
• 依托单位: Fachgebiet Technische Mineralogie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/310625331?language=en
• 关键词: Synthesis; single; crystal; structure; lattice

The isostructural R2X2Z2O(BO3)3 borates (RCOB) crystallize in the acentric space group Cm. They are potential high-temperature piezoelectrics, which show an unknown structural instability. The present project focuses on the synthesis and Czochralski growth of RCOB (X, Z = Ca, R = La, Y, Gd, Pr, Nd, Er). As a second part structure and lattice parameters will be determined as a function of temperature. Based on the lattice parameters, an atomistic model of thermal expansion will be established. The qualitative evaluation of the crystals by determination of dislocation densities and point defects is planned. In addition, the chemical composition of RCOB should be expanded by variations in the cation positions, which are recently limited to Ca and rare-earth elements. The close collaboration with the project partners should provide information concerning the structure-property-relationships.

同构R2 X2 Z2 O（BO 3）3硼酸盐（RCOB）以无中心空间群Cm结晶。它们是潜在的高温压电体，表现出未知的结构不稳定性。本项目主要研究RCOB（X，Z = Ca，R = La，Y，Gd，Pr，Nd，Er）晶体的合成和提拉生长。作为第二部分，结构和晶格参数将被确定为温度的函数。基于晶格参数，将建立热膨胀的原子模型。计划通过测定位错密度和点缺陷对晶体进行定性评价。此外，RCOB的化学组成应通过阳离子位置的变化来扩展，阳离子位置最近仅限于Ca和稀土元素。与项目合作伙伴的密切合作应提供有关结构-性能-关系的信息。

项目成果

Order/disorder processes and electromechanical properties of monoclinic GdCa4O(BO3)3

• DOI: 10.1515/zkri-2019-0026
• 发表时间: 2019-08
• 期刊: Zeitschrift für Kristallographie - Crystalline Materials
• 作者: M. Münchhalfen;J. Schreuer;C. Reuther;R. Möckel;J. Götze;E. Mehner;H. Stöcker;D. Meyer