화학공학소재연구정보센터
Journal of Materials Science, Vol.46, No.23, 7582-7587, 2011
Local inhomogeneity and surface degradation of Fe1.15Te and Fe1.03Te0.62Se0.38 single crystals
We have investigated the structural and magnetic properties of Fe1.15Te and Fe1.03Te0.62Se0.38 single crystals grown by slow cooling method using a specially designed double-walled quartz ampoule. X-ray diffraction reveals significant local inhomogeneity as a result of fractional substitution of Te site by Se in single crystal Fe1.03Te0.62Se0.38. The existence of superconductivity is confirmed for Se substitution to the Te site of Fe1.03Te0.62Se0.38 but with persistent Fe7Se8 impurity phase. Raman spectroscopy confirmed the surface structural instability when the samples were exposed to moderate laser irradiation in the atmospheric environment. With high intensity laser irradiation, Fe(Se, Te) compounds can be decomposed into Fe2O3 hematite phase.