1303.6833 (Rainer Frankovsky et al.)

Short range magnetic order and effective suppression of
superconductivity by manganese-doping in LaFe1-xMnxAsO1-yFy    [PDF]

Rainer Frankovsky, Hubertus Luetkens, Frank Tambornino, Alexey Marchuk, Gwendolyne Pascua, Alex Amato, Hans-Henning Klauss, Dirk Johrendt

We present a study of the structural and physical properties of directly hole doped LaFe1-xMnxAsO (x = 0.0-0.2) and the influence of charge compensation / electron-doping by additional F doping in LaFe0.9Mn0.1AsO1-yFy (y = 0.1-0.5). High quality polycrystalline samples were prepared using a solid state metathesis reaction. The unit cell increases upon Mn doping, but decreases again when additional F is inserted. The semiconducting character of LaFe1-xMnxAsO decreases with additional F doping. Muon spin relaxation (muSR) measurements reveal short range magnetic order in LaFe1-xMnxAsO and a suppression of magnetism by additional electron-doping with fluoride in LaFe0.9Mn0.1AsO1-yFy. Superconductivity remains absent even though the electronic preconditions are fulfilled in electron-doped LaFe0.9Mn0.1AsO1-yFy at x > 0.1, which is suggestive of effective pair breaking by Mn in this system.

View original: http://arxiv.org/abs/1303.6833