ARPES spectral function investigation of Cr- and Mn- substituted BaFe 2 As 2

Abstract The antiferromagnetic transition temperature (T AFM ) is suppressed similarly as a function of Cr or Mn content in Ba(Fe 1−x M x ) 2 As 2 ( M = Cr or Mn, CrBFA and MnBFA, respectively) for x values up to ∼ 0.12, despite the different electronic effects of these substitutions. Furthermore, superconductivity is not observed for either substitutions. We employed angle-resolved photoemission spectroscopy (ARPES) to address the Fermi surface (FS) evolution and electronic correlations in these materials. First, we inspect the roles of Cr and Mn as hole dopants. We show that incorporating Cr leads to an effective hole doping of the states near the FS, whereas no effective doping is observed for Mn incorporation. We then present and critically assess an analysis of the obtained ARPES spectral functions. We show how the ARPES spectra polarization dependence allows isolating a band contribution suitable for quantitative analysis of the spectral features. We characterize, in both cases, a fractional scaling of the imaginary part of self-energy as a function of the binding energy, a signature property of Hund’s correlations. We conclude that CrBFA and MnBFA are correlated systems for which the changes in the FS as a function of either Cr or Mn are unrelated to the evolution of T AFM .