Superconductivity Induced by Oxygen Doping in Y2O2Bi. (3rd April 2017)

• Record Type: Journal Article
• Authors: Cheng, Xiyue; Gordon, Elijah E.; Whangbo, Myung‐Hwan; Deng, Shuiquan
• Is Part Of: Angewandte Chemie. Volume 129:Number 34(2017)
• Page Start: 10257
• Page End: 10260
• Publication Date: 2017-04-03
• Subjects: Bandstrukturen -- First-Principles-Rechnungen -- Flache Bänder -- Supraleitung -- Yttriumbismutoxid; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201701427
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: When doped with oxygen, the layered Y2 O2 Bi phase becomes a superconductor. This finding raises questions about the sites for doped oxygen, the mechanism of superconductivity, and practical guidelines for discovering new superconductors. We probed these questions in terms of first‐principles calculations for undoped and O‐doped Y2 O2 Bi. The preferred sites for doped O atoms are the centers of Bi4 squares in the Bi square net. Several Bi 6p x / y bands of Y2 O2 Bi are raised in energy by oxygen doping because the 2p x / y orbitals of the doped oxygen make antibonding possible with the 6p x / y orbitals of surrounding Bi atoms. Consequently, the condition necessary for the "flat/steep" band model for superconductivity is satisfied in O‐doped Y2 O2 Bi.