화학공학소재연구정보센터
Applied Surface Science, Vol.254, No.1, 321-324, 2007
Nanoscale intrinsic heterogeneities in Ag-Ge-Se glasses and their correlation with physical properties
Ag-Ge-Se glass forming system is dominated by liquid immiscibility. Glasses in the Se-GeSe2-Ag2Se triangle may have different morphologies according to their composition. In this work inhomogeneous morphology is observed in Ag-r(Ge(x)Sel(1-y))(100-x) bulk glasses with y = 0.20, 0.25 at.% fraction. Electron microscopy reveals that the scale of heterogeneity strongly depends on the sample composition. The physical properties of these glasses are also dependent on their composition and can be easily correlated to their morphology. Accordingly, the electric conductivity evolves from semiconducting to ionic conductivity whereas a percolation transition occurs in a narrow Ag concentration range. Mossbauer spectrometry let us to analyse the local order of these intrinsically heterogeneous glasses employing 57 Fe as a probe. (C) 2007 Elsevier B.V. All rights reserved.