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Title: Lifshitz Transition and Chemical Instabilities in Ba1 xKxFe2As2 Superconductors

Forsolid-solutionBa1 xKxFe2As2FermisurfaceevolutionismappedviaBlochspectralfunctionscalculatedusingdensityfunctionaltheoryimplementedinKorringa-Kohn-Rostokermultiplescatteringtheorywiththecoherent-potentialapproximation.Spectralfunctionsrevealelectronicdispersion,topology,orbitalcharacter,andbroadening(electron-lifetimeeffects)duetochemicaldisorder.Dissolutionofelectroncylindersoccursnearx 0.9withanonuniform,topological(Lifshitz)transition,reducingtheinterbandinteractions;yetthedispersionmaintainsitsdxzordyzcharacter.Formationenergiesindicatealloyingatx 0.35,asobserved,andatendencyforsegregationontheK-rich(x>0.6)side,explainingthedifficultyofcontrollingsamplequalityandtheconflictingresultsbetweencharacterizedelectronicstructures.OurresultsrevealFermisurfacetransitionsinalloyedsamplesthatinfluencestonodalsuperconductivityandsuggesttheoriginfordeviationsofcommontrendsinFe-basedsuperconductors,suchasBud ko-Ni-Canfieldscaling.
Authors:
 [1] ;  [1]
  1. University of Illinois, Urbana-Champaign
Publication Date:
OSTI Identifier:
1127403
DOE Contract Number:
DE-AC05-00OR22725
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review Letters; Journal Volume: 112; Journal Issue: 15
Research Org:
Oak Ridge National Laboratory (ORNL)
Sponsoring Org:
SC USDOE - Office of Science (SC)
Country of Publication:
United States
Language:
English