2004/09/30 by U. Vempati, U Vempati, P. Boolchand +1 · 20 citations
Materials Science · Physics and Astronomy · #Atmospheric temperature range #Chalcogenide #Differential scanning calorimetry #Enthalpy #Glass properties and applications #Phase (matter) #Phase-change materials and chalcogenides #Raman scattering #Raman spectroscopy #Selenide #Solid-state spectroscopy and crystallography #Ternary operation #cond-mat.dis-nn #cond-mat.mtrl-sci
paper · pdf · doi:10.1088/0953-8984/16/44/010
published in Journal of Physics Condensed Matter 16(44), S5121-S5138 (IOP Publishing) · 1 PDF file has text, 9 figures and 3 tables
openalex publication_date 2004/10/23 · arxiv created 2005/02/09 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Ge x P x S 1−2 x glasses in the compositional range have been synthesized and examined in temperature modulated differential scanning calorimetry (MDSC) and Raman scattering experiments. Trends in the non-reversing enthalpy Δ H nr ( x ) near T g show the term to almost vanish in the 0.090(5)< x <0.135(5) range, and to increase by an order of magnitude at x <0.09, and at x >0.135. In analogy to previous results on chalcogenide glasses, we identify compositions at x <0.09 to be elastically floppy , those in the 0.090< x <0.135 range to be in the intermediate phase , and those at x >0.135 to be stressed rigid . MDSC results also show that the Δ H nr term ages in the stressed-rigid and floppy phases but not in the intermediate phase. The intermediate phase is viewed to be a self-organized phase of a disordered network. It consists of at least four isostatically rigid local structures: corner-sharing GeS 4 , edge-sharing GeS 2 , pyramidal P(S 1/2 ) 3 and quasi-tetrahedral S = P(S 1/2 ) 3 units for which evidence comes from Raman scattering. The latter method also shows the existence of P 4 S 7 and P 4 S 10 molecules in the glasses segregated from the backbone. These aspects of structure contribute to an intermediate phase that is significantly narrower in width than in the corresponding selenide glasses.