High-pressure single crystal growth and characterization of the 1111-type iron-pnictide superconductors and related systems

1111型铁磷超导体及相关系统的高压单晶生长和表征

• 批准号: 168510622
• 负责人: Professor Dr. Cornelius Krellner
• 金额: --
• 依托单位: Physikalisches Institut
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/168510622?language=en
• 关键词: pressure; single; crystal; growth; characterization

The single crystal growth of doped and undoped LnFeAsO (Ln=La, Ce,…) compounds was found to be very challenging, slowing down the scientific progress in this type of compounds. In this project within the priority program, we will use our particular experience with a high-temperature Sn-flux method which we have already developed for the homologue compounds CeTPO (T=Fe, Ru, Os, Co) to grow larger single crystals of the LnFeAsO materials. We will focus on the sustained optimization of the crystal growth parameters, e.g., the stoichiometry of the melt, the temperature profile, the material of the crucible, and others to obtain mm-size single crystals of highest possible quality. The quality of the crystals will be determined with various state of the art X-ray techniques as well as physical characterization including resistivity, specific-heat, and magnetization measurements. The single crystals will be the basis for many other projects within the priority program, e.g., photoelectron spectroscopy, neutron techniques, optical and ultrasonic measurements, thermal expansion, and quantum oscillations using partly long-standing collaborations with colleagues throughout Germany to significantly advance the understanding of this outstanding materials-class.

发现掺杂和未掺杂LnFeAsO （Ln=La, Ce，…）化合物的单晶生长非常具有挑战性，减缓了这类化合物的科学进展。在优先项目的这个项目中，我们将利用我们在高温sn通量法方面的特殊经验，我们已经为同类化合物CeTPO （T=Fe, Ru, Os, Co）开发了一种更大的LnFeAsO材料单晶。我们将重点关注晶体生长参数的持续优化，例如，熔体的化学计量，温度分布，坩埚的材料等，以获得尽可能高质量的毫米大小的单晶。晶体的质量将由各种先进的x射线技术以及包括电阻率、比热和磁化测量在内的物理特性来确定。这些单晶将成为优先项目中许多其他项目的基础，例如光电子能谱、中子技术、光学和超声波测量、热膨胀和量子振荡，通过与德国各地的同事进行部分长期合作，显著推进对这一杰出材料类别的理解。