Electronic and magnetic properties of the new iron-based superconductor [Li1-xFexOH]FeSe
I. A. Nekrasov+, M. V. Sadovskii+* 1)
+Institute for Electrophysics UB of the RAS, 620016 Ekaterinburg, Russia
*Institute for Metal Physics UB of the RAS, 620290 Ekaterinburg, Russia
Abstract
We present the results of paramagnetic LDA band structure calculations:
band dispersions, densities of states and Fermi surfaces, for the new iron
based high-temperature superconductor LiOHFeSe.
Main structural motif providing bands in the vicinity
of the Fermi level is FeSe layer which is isostructural to the bulk FeSe
prototype superconductor. The bands crossing the Fermi level and Fermi surfaces
of the new compound are typical for other iron based superconductors.
Experimentally it was shown that introduction of Fe ions into LiOH layer
gives rise to ferromagnetic ordering of the Fe ions at TC=10 K.
To study
magnetic properties of [Li0.8Fe0.2OH]FeSe system we have performed
LSDA calculations for superlattice and found
ferromagnetism within the Li4Fe(OH) layer. To estimate the Curie temperature
we obtained Fe-Fe exchange interaction parameters for Heisenberg model from our
LSDA calculations, leading to theoretical value of Curie temperature 10.4 K in
close agreement with experiment.