PMID- 24605917
OWN - NLM
STAT- PubMed-not-MEDLINE
DCOM- 20141121
LR  - 20140403
IS  - 1520-5207 (Electronic)
IS  - 1520-5207 (Linking)
VI  - 118
IP  - 13
DP  - 2014 Apr 3
TI  - Short range structural models of the glass transition temperatures and densities 
      of 0.5Na2S + 0.5[xGeS2 + (1 - x)PS5/2] mixed glass former glasses.
PG  - 3710-9
LID - 10.1021/jp411942t [doi]
AB  - The 0.5Na2S + 0.5[xGeS2 + (1 - x)PS5/2] mixed glass former (MGF) glass system 
      exhibits a nonlinear and nonadditive negative change in the Na(+) ion 
      conductivity as one glass former, PS5/2, is exchanged for the other, GeS2. This 
      behavior, known as the mixed glass former effect (MGFE), is also manifest in a 
      negative deviation from the linear interpolation of the glass transition 
      temperatures (T(g)) of the binary end-member glasses, x = 0 and x = 1. 
      Interestingly, the composition dependence of the densities of these ternary MGF 
      glasses reveals a slightly positive MGFE deviation from a linear interpolation of 
      the densities of the binary end-member glasses, x = 0 and x = 1. From our 
      previous studies of the structures of these glasses using IR, Raman, and NMR 
      spectroscopies, we find that a disproportionation reaction occurs between 
      PS7/2(4-) and GeS3(2-) units into PS4(3-) and GeS5/2(1-) units. This 
      disproportionation combined with the formation of Ge4S10(4-) anions from 
      GeS5/2(1-) groups leads to the negative MGFE in T(g). A best-fit model of the 
      T(g)s of these glasses was developed to quantify the amount of GeS5/2(1-) units 
      that form Ge4S10(4-) molecular anions in the ternary glasses ( approximately  5-10%). This 
      refined structural model was used to develop a short-range structural model of 
      the molar volumes, which shows that the slight densification of the ternary 
      glasses is due to the improved packing efficiency of the germanium sulfide 
      species.
FAU - Bischoff, Christian
AU  - Bischoff C
AD  - Department of Materials Science and Engineering Iowa State University Ames, Iowa 
      50011, United States.
FAU - Schuller, Katherine
AU  - Schuller K
FAU - Martin, Steve W
AU  - Martin SW
LA  - eng
PT  - Journal Article
DEP - 20140325
PL  - United States
TA  - J Phys Chem B
JT  - The journal of physical chemistry. B
JID - 101157530
EDAT- 2014/03/13 06:00
MHDA- 2014/03/13 06:01
CRDT- 2014/03/11 06:00
PHST- 2014/03/11 06:00 [entrez]
PHST- 2014/03/13 06:00 [pubmed]
PHST- 2014/03/13 06:01 [medline]
AID - 10.1021/jp411942t [doi]
PST - ppublish
SO  - J Phys Chem B. 2014 Apr 3;118(13):3710-9. doi: 10.1021/jp411942t. Epub 2014 Mar 
      25.