| The intermediate phase in ternary GexAsxSe1-2x glasses. in "Supercooled Liquids, Glass Transition and Bulk Metallic Glasses" (eds (2003) | |||||||||||||||
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| Melt-quenched AsxGexSe1-2x glasses over the composition range, 0 < x < 0.26, are examined in Raman scattering, T-modulated Differential Scanning Calorimetry (MDSC), and 119 Sn Mossbauer spectroscopy measurements. The non-reversing enthalpy near Tg, ∆Hnr(x), accessed from MDSC shows a global minimum ( ~ 0) in the xc(1) = 0.09 < x < xc(2) = 0.16 range, and increases by an order of magnitude both at x < xc(1) and at x> xc(2). Raman mode frequency of corner-sharing Ge(Se1/2)4 tetrahedra studied as a function of x, also shows three distinct regimes (or power-laws, p) that coincide with ∆Hnr(x) trends. These regimes are identified with mechanically floppy (x < xc(1)), intermediate (xc(1) < x < xc(2)), and stressed-rigid (x> xc(2)) phases. The Raman elasticity power-law in the intermediate phase,p1 = 1.04(3), and in the stressed rigid phase, p2 = 1.52(5), suggest effective dimensionalities of d = 2 and 3 respectively. STRUCTURE BASED CLASSIFICATION OF GLASSES In the early 1980s, Phillips [1] and independently Thorpe [2] suggested that a network of polymeric chains (weakly crosslinked) will spontaneously stiffen or become rigid | |||||||||||||||
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