Mossbauer Spectroscopy Determination of iron foreign phases in the Superconducting Systems; RAsFeO1-x, RAsFeO1-xFx and Sr1-xKxFe2As2

摘要

The recently discovered superconducting - spin density wave materials,containing Fe and As, have raised huge interest. However most materialsprepared to date, suffer from a varying degree of content of foreign Fe-Asphases, Fe2As, FeAs2 and FeAs, which can lead to wrong conclusions concerningthe properties of these materials. We show here that Mossbauer Spectroscopy isable to determine quite easily the relative content of the foreign phases. Thisprocedure is demonstrated by a study of seven samples of superconducting orspin density wave materials, prepared in three different laboratories.