Electronic and magnetic structure of possible iron based superconductor BaFe2Se3
M. V. Medvedev+, I. A. Nekrasov+, M. V. Sadovskii+×
+Institute for Electrophysics RAS, Ural Branch, 620016 Ekaterinburg, Russia
×Institute for Metal Physics RAS, Ural Branch, 620990 Ekaterinburg, Russia
We present results of LDA-calculations (band structure, densities of states,
Fermi surfaces) for possible iron based superconductor BaFe2Se3 (Ba123)
in normal (paramagnetic) phase. Results are briefly compared with similar data
on prototype BaFe2As2 and (K,Cs)Fe2Se2 superconductors.
Without doping this system is antiferromagnetic
with K and rather complicated magnetic structure.
Neutron diffraction experiments indicated the possibility of two possible
spin structures (antiferromagnetically ordered "plaquettes" or "zigzags"),
indistinguishable by neutron scattering. Using LSDA calculated exchange
parameters we estimate Neel temperatures for both spin structures within the
molecular field approximation and show τ1 ("plaquettes") spin
configuration to be more favorable than τ2 ("zigzags").