Koz, C.Rößler, S.Wirth, S.Schwarz, U.2018-04-122018-04-1220171557-1939http://hdl.handle.net/11693/37466The 11-type Fe-chalcogenides belong to the family of Fe-based superconductors. In these compounds, the interstitial Fe is known to strongly influence the magnetic and superconducting properties. Here, we present the chemical homogeneity range of ternary compounds Fe1 + yTe1−xSex based on powder x-ray diffraction, energy dispersive x-ray analysis, and magnetization measurements. Our investigations show that the maximum amount of excess Fe in homogeneous Fe1 + yTe1−xSex decreases with increase in Se substitution for Te. Using our synthesis procedure, single-phase Fe1 + yTe1−xSex, with 0.5 ≤ x < 1 could not be formed for any amount of excess Fe. Further, the superconducting volume fraction in the material is found to be strongly suppressed by excess Fe.EnglishFe-based superconductorsFe-chalcogenidesTernary phase diagramChalcogenidesChemical analysisChemical compoundsEnergy dispersive x-ray analysisInorganic compoundsSuperconducting materialsTernary alloysX ray analysisX ray diffractionChemical homogeneityMagnetization measurementsPowder x-ray diffractionSuperconducting propertiesSuperconducting volumeSynthesis procedureIron compoundsArticle10.1007/s10948-016-3632-x1557-1947