Pereira Zenner S, Faccin Giovani M, da Silva E Z
Departamento de Ciência e Tecnologia, Universidade Federal Rural do Semi-Árido (UFERSA), CEP 59780-000, Campus Caraúbas, RN, Brazil.
Faculdade de Ciências Exatas e Tecnológicas, Universidade Federal da Grande Dourados - Unidade II, CP 533, 79804-970, Dourados, MS, Brazil.
Nanoscale. 2022 Jun 23;14(24):8594-8600. doi: 10.1039/d2nr00395c.
Superconductivity in low dimensional materials and 2D electrides are topics of great interest with possible applications in next generation electronic devices. Using density functional theory (DFT) associated with Migdal-Eliashberg approach and maximally localized Wannier functions this study shows how biaxial strain affects superconductivity in a monolayer of MoN. Results indicate that 2D MoN presents strong electron-phonon coupling with large anisotropy in the superconducting energy gap. It is also proposed that, at low temperatures, a single layer of MoN becomes an electride with localized electron gas pockets on the surface, resembling anions adsorbed on an atomic sheet. Calculations point to = 24.7 K, a record high transition temperature for this class of material at ambient pressure. Furthermore, it is shown that when biaxial strain is applied to a superconducting MoN monolayer, a new superconductivity gap starts at 2% strain and is enhanced by continuum strain, opening additional coupling channels.
低维材料中的超导性和二维电子化物是备受关注的课题，在下一代电子设备中可能具有应用价值。本研究采用与Migdal-Eliashberg方法相关联的密度泛函理论（DFT）以及最大局域化Wannier函数，展示了双轴应变如何影响单层MoN中的超导性。结果表明，二维MoN呈现出强电子-声子耦合，在超导能隙中具有大的各向异性。还提出，在低温下，单层MoN成为一种电子化物，其表面存在局域化电子气口袋，类似于吸附在原子片上的阴离子。计算得出转变温度Tc = 24.7 K，这是此类材料在常压下的创纪录高温。此外，研究表明，当对超导MoN单层施加双轴应变时，新的超导能隙在2%应变时开始出现，并随着连续应变而增强，开启了额外的耦合通道。
