Phase separation in the iron chalcogenide superconductor Fe<sub>1+<i>y</i></sub>Te<sub><i>x</i></sub>Se<sub>1โ<i>x</i></sub>
Phase separation in the iron chalcogenide superconductor Fe<sub>1+<i>y</i></sub>Te<sub><i>x</i></sub>Se<sub>1โ<i>x</i></sub>
We report investigation on Fe1+yTexSe1-x single crystals by using scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS). Both nonsuperconducting samples with excess iron and superconducting samples demonstrate nanoscale phase separation and chemical inhomogeneity of Te/Se content, which we attribute to a miscibility gap. The line scan EELS โฆ