Related papers: Intermediate phase, network demixing, boson and fl…
Raman scattering, IR reflectance and modulated DSC measurements are performed on specifically prepared dry (AgI)x(AgPO3)1-x glasses over a wide range of compositions 0 < x < 0.60. A reversibility window is observed in the 0.095< x < 0.378…
GexPxS1-2x glasses in the compositional range 0.05 < x < 0.19 have been synthesized and examined in temperature modulated differential scanning calorimetry (MDSC) and Raman scattering experiments. Trends in the non-reversing enthalpy…
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 119Sn Mossbauer spectroscopy measurements. The non-reversing enthalpy…
Bulk glass formation occurs over a very small part of phase space, and "good" glasses (which form even at low quench rates ~ 10K/sec) select an even smaller part of that accessible phase space. An axiomatic theory provides the physical…
A Raman profiling method is used to monitor growth of GexSe100-x melts and reveals a two step process of homogenization. Resulting homogeneous glasses show the non-reversing enthalpy at Tg, {\Delta}Hnr(x), to show a square-well like…
Raman and calorimetric studies on Ge_xSe_{1-x} glasses have provided evidence for the existence of the intermediate phase (IP) in chalcogenide and other glasses. Here, we present X-Ray Absorption Near Edge Structure (XANES) measurements on…
Raman scattering on bulk AsxS1-x glasses showes that vibrational modes of As4S4 monomer first appear near x=0.38, and their concentration increases precipitously with increasing x, suggesting that the stoichiometric glass (x=0.40) is…
We review Intermediate Phases (IPs) in chalcogenide glasses and provide a structural interpretation of these phases. In binary group IV selenides, IPs reside in the 2.40 < r < 2.54 range, and in binary group V selenides they shift to a…
An experimental study of optical phonon modes, both normal and interface (IF) phonons, in bilayer strain-coupled InAs/GaAs_(1-x)Sb_x quantum dot heterostructures has been presented by means of low-temperature polarized Raman scattering. The…
A theoretical and experimental study of the Intermediate Phase (IP) in GexSe1-x is presented. Based on ab initio molecular dynamics (MD) models of these glasses, a generic atomic picture of the IP is discussed thoroughly. X-Ray Absorption…
The rigid to floppy transitions and the associated intermediate phase in glasses are studied in the case where the local structure is not fully determined from the macroscopic concentration. The approach uses size increasing cluster…
Three elastic phases of covalent networks, (I) floppy, (II) isostatically rigid and (III) stressed-rigid have now been identified in glasses at specific degrees of cross-linking (or chemical composition) both in theory and experiments. Here…
Alkaline earth silicate glasses $xCaO-(1-x)SiO_2$ exhibit a well marked threshold in Raman lineshapes which can be related to the onset of network rigidity as the concentration of calcium oxide $x$ is decreased. The present results are…
Modulated DSC measurements on bulk (Na2O)x(GeO2)1-x glasses show a sharp reversibility window in the 14% < x < 19% soda range, which correlates well with a broad global minimum in molar volumes. Raman and IR reflectance TO and LO mode…
Near-bandgap Raman scattering was used to induce and study photostructural changes in AsxS100-x bulk glasses revealing a new photoinduced polymerization effect. Raman spectra were recorded also in off-resonant conditions allowing for a…
The scaling behavior of the so-called boson peak in glass-formers and its relation to the elastic properties of the system remains a source of controversy. Here, the boson peak in a binary reactive mixture is measured by Raman scattering…
The non-reversing enthalpy near Tg, DHnr, in bulk GexAsxS1-2x glasses is found to display a global minimum (~0) in the 0.11 < x < 0.15 range, the reversibility window. Furthermore, the DHnr term is found to age for glass compositions both…
We investigate the properties of the glass phase of a recently introduced spin glass model of soft spins subjected to an anharmonic quartic local potential, which serves as a model of low temperature molecular or soft glasses. We solve the…
The vibrational properties of three sodosilicate glasses have been investigated in the framework of Density Functional Theory. The pure vibrational density of states has been calculated for all systems and the different vibrational modes…
We have systematically investigated the optical properties of the InP1-xBix ternary alloys with 0<x<2.46%, using high resolution polarized Raman scattering measurement. Both InP-like and InBi-like optical vibration modes (LO) were…