Proton conductivity in hydrous and anhydrous thiogermanic acids

Poling, Steven A.; Nelson, Carly R.; Sutherland, Jacob T.; Martin, Steve W.

doi:10.1016/j.ssi.2004.02.021

Cited by 8 publications

(4 citation statements)

References 8 publications

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“…The suggestion here is that not all bS are equal in that if the bS do not “propagate” out into the longer range structure of the glass, then the rigidity of the network will not necessarily be increased and Tg may not increase. We have such a possibility in these glasses through the formation Ge 4 S 10 4‑ molecular anions. − These structural groups are superstructures of Ge 3 groups which we have shown must be present to properly account for all of the vibrational spectral features of these glasses and for this reason are included in our SRO model of the structures of these glasses. As seen in Figure , these units possess 1.5 bS per germanium, as expected for this composition, but none-the-less do not constitute fully network bridging bS structures in these glasses.…”

Section: Discussionmentioning

confidence: 97%

Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

2014

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The 0.5Na 2 S + 0.5[xGeS 2 + (1 -x)PS 5/2 ] mixed glass former (MGF) glass system exhibits a nonlinear and nonadditive negative change in the Na + ion conductivity as one glass former, PS 5/2 , is exchanged for the other, GeS 2 . 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 PS 7/2 4-and GeS 3 2-units into PS 4 3-and GeS 5/2 1-units. This disproportionation combined with the formation of Ge 4 S 10 4-anions from GeS 5/2 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 GeS 5/2 1-units that form Ge 4 S 10 4-molecular anions in the ternary glasses (∼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. Disciplines Materials Science and Engineering CommentsReprinted with permission ABSTRACT: The 0.5Na 2 S + 0.5[xGeS 2 + (1 − x)PS 5/2 ] mixed glass former (MGF) glass system exhibits a nonlinear and nonadditive negative change in the Na + ion conductivity as one glass former, PS 5/2 , is exchanged for the other, GeS 2 . 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 PS 7/2 4-and GeS 3 2-units into PS 4 3-and GeS 5/2 1-

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Section: Discussionmentioning

confidence: 97%

Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

2014

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“…Poling et al have reported proton conductivity in the thiogermanic acids, H 4 Ge 4 S 10 and H 2 Ge 4 S 9 and their hydrated analogues. 154 The hydrated phases showed the highest proton conductivities (10 210 to 10 23 S cm 21 in the temperature range 255 to 125 uC), attributed to the presence of loosely bound water.…”

Section: Other Systemsmentioning

confidence: 93%

24 Conducting solids

Sansom

Slater

2005

Annu. Rep. Prog. Chem., Sect. A

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“…GeS 2 ‐based glasses show interesting electrical and optical properties, and their low phonon energy makes them suitable for optical fiber amplification 5, 6. Moreover, GeS 2 displays good potentiality for applications such as fast ion‐conducting glasses7, 8 and proton‐conducting membranes 9, 10…”

Section: Introductionmentioning

confidence: 99%

Ion/Molecule reactions in SiH₄/H₂S and GeH₄/H₂S mixtures

et al. 2009

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The gas phase ion chemistry of silane/hydrogen sulfide and germane/hydrogen sulfide mixtures was studied by ion trap mass spectrometry (ITMS), in both positive and negative ionization mode. In positive ionization, formation of X/S (X = Si, Ge) mixed ions mainly takes place via reactions of silane or germane ions with H(2)S, through condensation followed by dehydrogenation. This is particularly evident in the system with silane. On the other side, reactions of H(n)S(2)(+) ions with XH(4) (X = Si, Ge) invariably lead to formation of a single X-S bond. In negative ionization, a more limited number of mixed ion species is detected, but their overall abundance reaches appreciable values, especially in the SiH(4)/H(2)S system. Present results clearly indicate that ion processes play an important role in formation and growth of clusters eventually leading to deposition of amorphous solids in chemical vapor deposition (CVD) processes.

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Proton conductivity in hydrous and anhydrous thiogermanic acids

Cited by 8 publications

References 8 publications

Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

24 Conducting solids

Ion/Molecule reactions in SiH₄/H₂S and GeH₄/H₂S mixtures

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Proton conductivity in hydrous and anhydrous thiogermanic acids

Cited by 8 publications

References 8 publications

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

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

24 Conducting solids

Ion/Molecule reactions in SiH4/H2S and GeH4/H2S mixtures

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Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

Short Range Structural Models of the Glass Transition Temperatures and Densities of 0.5Na₂S + 0.5[xGeS₂ + (1 – x)PS_5/2] Mixed Glass Former Glasses

Ion/Molecule reactions in SiH₄/H₂S and GeH₄/H₂S mixtures