2012/09/26 by Xiao-Jia Chen, Xiao‐Jia Chen, Feng-Jiang Jia +25
Materials Science · Physics and Astronomy · #FOS: Physical sciences #Iron-based superconductors research #Rare-earth and actinide compounds #Strongly Correlated Electrons (cond-mat.str-el) #Superconductivity (cond-mat.supr-con) #Superconductivity in MgB2 and Alloys #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.48550/arxiv.1209.6028
8 pages, 6 figures
arxiv created 2012/09/26 · openalex publication_date 2012/09/26 · arxiv updated 2012/09/27 · openalex created_date 2016/11/30 · openalex updated_date 2026/07/28
The superconducting, transport, and structural properties of optimally electron-doped BaFe1.9Ni0.1As2 are investigated by combining the electrical resistance and synchrotron X-ray diffraction measurements at high pressures. The superconducting transition temperature of this system is found to decrease in a similar way of the axial ratio of c/a with increasing pressure but vanishing at a critical pressure of 7.5 GPa where c/a has a dip and an isostructural transformation from a tetragonal to a collapsed tetragonal phase takes place. The resistance is found to obey a linear temperature dependence, evidencing the antiferromagnetic spin-fluctuations transport mechanism. The pressure effects are interpreted within the framework of pressure-induced Fermi surface topology modification in which pressure suppresses both the quasiparticle effective mass and the strength of the antiferromagnetic spin fluctuations leading to the reduction of superconductivity, accordingly. The absent superconductivity in the collapsed tetragonal phase is suggested to result from the complete suppression of the antiferromagnetic spin fluctuations.