EAGER: SUPER: Non-Hexagonal 2D Boride and Borocarbide Superconductors

非技术总结与此项目，由材料研究部，教授的支持。爱荷华州州立大学的Kirill Kovnir、Kai Ming Ho和弗拉基米尔Antropov及其研究小组将专注于发现新型高温超导体，这将极大地造福社会。在环境压力下稳定的高温超导体有可能在许多与能源相关的领域彻底改变现代技术：发电，传输，转换和运输。这种超导材料目前还不可用。以前对传统超导体的广泛研究表明，基于轻元素（如氢、碳和硼）的系统有希望。在目前的项目中，计算和实验的努力结合起来，以寻找新的超导体之间的层状硼化物和硼碳化物的两种或多种过渡金属。这些特定的目标系统是严重不足的研究，并持有承诺的金属或硼/碳取代的方式来调整材料的性能。拟议的研究整合了计算和实验研究，为研究生研究人员提供多样化的培训。该项目中考虑的基本问题适用于紧急能源技术。所获得的知识和既定的方法可能适用于其他领域的功能材料开发。该项目由材料研究部支持，重点是在两种或多种过渡金属的非六方硼化物和硼碳化物中发现高温超导体。不同过渡金属的组合允许实现基于5-和7-元B环的层，从而提供调节硼网络中的电子-声子相互作用的杠杆。对新超导体的研究始于对三元和多元金属硼化物和硼碳化物的广泛计算筛选，这些金属硼化物和硼碳化物含有至少两种不同的过渡金属，具有非六方B或B-C层。采用自适应遗传算法和快速先进的机器学习算法相结合的方法对大量硼化物和硼碳化物进行筛选。有前途的候选人进行了评估，由更高层次的理论和相关的电子-声子超导性（态密度，声子频率，电子-声子耦合）的属性估计使用DFT。 使用DFT的结果，选定的候选人进行实验合成和表征。实验反馈提供给结构优化和超导小组，以进一步估计在过渡金属亚晶格中通过异价取代优化电子-声子相互作用的潜在途径（为了调节电子特性），和硼亚晶格（硼/碳取代以调节声子相互作用）该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

NON-TECHNICAL SUMMARYWith this project, supported by Division of Materials Research, Profs. Kirill Kovnir, Kai Ming Ho, and Vladimir Antropov and their research groups at Iowa State University will be focused on the discovery of novel high-temperature superconductors which will greatly benefit society. High-temperature superconductors which are stable at ambient pressure have the potential to revolutionize modern technology in many energy-related fields: generation, transmittance, transformation, and transportation. Such superconducting materials are currently unavailable. Extensive previous studies on conventional superconductors pointed to promise of the systems based on light elements, such as hydrogen, carbon, and boron. In the current project, computational and experimental efforts are joined to find novel superconductors among layered borides and borocarbides of two or more transition metals. These particular target systems are severely understudied, and hold promise for tuning of the materials properties by means of metal or boron/carbon substitutions. The proposed research integrates computational and experimental studies to provide diverse training for graduate student researchers. The fundamental issues considered in the project are applicable to emergent energy technology. The acquired knowledge and established methodology may be applicable for functional materials development in other areas. TECHNICAL SUMMARYThis project, supported by the Division of Materials Research, is focused on the discovery of high-temperature superconductors in non-hexagonal borides and borocarbides of two or more transition metals. A combination of different transition metals allowed for realization of layers based on 5- and 7-membered B rings providing a lever to tune electron-phonon interactions in the boron network. The search for new superconductors starts with the wide computational screening of ternary and multinary metal borides and borocarbides containing at least two different transition metals with non-hexagonal B or B-C layers. A combination of Adaptive Genetic Algorithm and fast advanced machine learning algorithms is used to screen a large number of boride and borocarbides. The promising candidates are evaluated by higher-level theory and the properties relevant for the electron-phonon superconductivity (density of states, phonon frequencies, electron-phonon coupling) are estimated using DFT. Using the DFT result, selected candidates are experimentally synthesized and characterized. The experimental feedback is provided both to structural optimization and superconductivity groups to further estimate potential ways of optimizing electron-phonon interaction by aliovalent substitutions, in both, transition metal sublattice (to tune electronic properties), and boron sublattice (boron/carbon substitutions to tune phonon interactions).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.