Analyses of intrinsic heterogeneities and metal segregation in samples of Ag-Ge-Se glasses

J. M. CONDE GARRIDO; J. A. ROCCA; M. ERAZÚ; M. A. UREÑA; M. FONTANA; B. ARCONDO

Buenos Aires, Argentina

Congreso; At the Frontiers of the Condensed Matter IV; 2008

Centro Atómico Constituyentes, Comisión Nacional de Energía Atómica

<!-- /* Style Definitions */ p.MsoNormal, li.MsoNormal, div.MsoNormal {mso-style-parent:""; margin:0cm; margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:12.0pt; font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";} @page Section1 {size:612.0pt 792.0pt; margin:70.85pt 3.0cm 70.85pt 3.0cm; mso-header-margin:36.0pt; mso-footer-margin:36.0pt; mso-paper-source:0;} div.Section1 {page:Section1;} --> GeySe(1-y) glasses are semiconductors but when Ag is added above certain threshold concentration, Agx[GeySe(1-y)](100-x) glasses behave as fast ionic conductors [1]. This peculiar behavior may be attributed to the intrinsically inhomogeneous nature of these glasses where zones rich in metals coexist with zones of the host material. The conductivity transformation may be ascribed to the percolation of the Ag rich phase [2]. Agx[Ge0.25Se0.75](100-x) glasses either massive or as films were obtained by melt quenching and pulsed laser deposition respectively in compositions belonging to the Se rich corner of the ternary phase diagram. Their amorphous nature and intermediate range order was checked employing X-ray diffractometry (XRD), the short range order was characterized by Extended X-ray Absorption Fine Structure (EXAFS) (Ge and Se K absorption border), and their microstructure was characterized by Scanning Electron Microscopy (SEM) and Small Angle X-ray Scattering (SAXS).