1306.4222 (M. Merz et al.)

To dope or not to dope: Electronic structure of Ba-site and Fe-site
substituted single-crystalline BaFe2As2    [PDF]

M. Merz, P. Schweiss, P. Nagel, Th. Wolf, H. v. Loehneysen, S. Schuppler

The substitutional dependence of (Ba,K)(Fe,TM)2As2 (TM = Mn, Co, Ni, and Cu) is investigated with single-crystal x-ray diffraction and with near-edge x-ray absorption fine structure at the TM and Fe L2,3 edges. The present study shows that only for Ba/K replacement charge carriers are directly doped to Fe 3d states. In the case of Fe/Co substitution the additional electrons contribute to the ensemble of all 3d electrons and seem to screen the impurity whereas for Fe/Mn, Fe/Ni, and Fe/Cu replacement the data indicate that TM 4s/4p-derived impurity states become important for the electronic structure of Fe-site substituted BaFe2As2.

View original: http://arxiv.org/abs/1306.4222