Novel magnesium borides and their superconductivity
M. M. Davari Esfahani, Q. Zhu, H. Dong, A. R. Oganov, S. Wang, M. S. Rakitin, X-F. Zhou
(Submitted on 7 Feb 2017)
With the motivation of searching for new superconductors in the Mg-B system, we performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0-200 GPa. We found a number of previously unknown, yet thermodynamically stable, compositions: MgB3, Mg3B10 and Mg2B7. We observed transition from semiconducting Pnma-MgB4 to superconducting C2/m-MgB4 at the elevated pressure of 31 GPa. Surprisingly, for each stable compound there is a phase with a boron sandwich structure analogous to AlB2-type structure. However, with the exception of MgB2, all other magnesium borides have low electron-phonon coupling constants λ of 0.32 to 0.39 and are predicted to have Tc below 3 K.
Comments: 13 pages, 10 figures. This manuscript has Supplemental Materials
Subjects: Superconductivity (cond-mat.supr-con)
Cite as: arXiv:1702.02221 [cond-mat.supr-con]
(or arXiv:1702.02221v1 [cond-mat.supr-con] for this version)
mrakitin
commented
6 years ago
https://arxiv.org/abs/1702.02221
Novel magnesium borides and their superconductivity M. M. Davari Esfahani, Q. Zhu, H. Dong, A. R. Oganov, S. Wang, M. S. Rakitin, X-F. Zhou (Submitted on 7 Feb 2017)
With the motivation of searching for new superconductors in the Mg-B system, we performed ab initio evolutionary searches for all the stable compounds in this binary system in the pressure range of 0-200 GPa. We found a number of previously unknown, yet thermodynamically stable, compositions: MgB3, Mg3B10 and Mg2B7. We observed transition from semiconducting Pnma-MgB4 to superconducting C2/m-MgB4 at the elevated pressure of 31 GPa. Surprisingly, for each stable compound there is a phase with a boron sandwich structure analogous to AlB2-type structure. However, with the exception of MgB2, all other magnesium borides have low electron-phonon coupling constants λ of 0.32 to 0.39 and are predicted to have Tc below 3 K.
Comments: 13 pages, 10 figures. This manuscript has Supplemental Materials Subjects: Superconductivity (cond-mat.supr-con) Cite as: arXiv:1702.02221 [cond-mat.supr-con] (or arXiv:1702.02221v1 [cond-mat.supr-con] for this version)