2017/01/31 by Yusuke Yanagisawa, Masashi Tanaka, Aichi Yamashita +6
Chemistry · Materials Science · Physics and Astronomy · #Analytical Chemistry (journal) #Chemistry #Condensed matter physics #Iron-based superconductors research #Materials science #Metallurgy #Microstructure #Phase (matter) #Physics #Quenching (fluorescence) #Superconductivity #Transition temperature #Vacancy defect #cond-mat.supr-con
paper · pdf · doi:10.7566/jpsj.86.043703
published as J. Phys. Soc. Jpn. 86, 043703 (2017)
openalex created_date 2017/02/03 · openalex publication_date 2017/03/16 · arxiv created 2017/03/18 · arxiv updated 2017/03/21 · openalex updated_date 2026/08/05
KxFe2-ySe2 exhibits an iron-vacancy ordering at T\rm s ∼270degC and separates into two phases: a minor superconducting (iron-vacancy-disordered) phase and a major non-superconducting (iron-vacancy-ordered) phase. The microstructural and superconducting properties of this intermixture can be tuned by an appropriate control of the quenching process through T\rm s. A faster quenching rate leads to a finer microstructure and a suppression of formation of the non-superconducting phase by up to 50%. Nevertheless, such a faster cooling rate does induce a monotonic reduction in the superconducting transition temperature (from 30.7 K down to 26.0 K) and, simultaneously, a decrease in the iron content within the superconducting phase such that the compositional ratio changed from K0.35Fe1.83Se2 to K0.58Fe1.71Se2.