PlumX Metrics
Embed PlumX Metrics

Structural and thermodynamic similarities of phases in the Li–Tt (Tt = Si, Ge) systems: Redetermination of the lithium-rich side of the Li–Ge phase diagram and crystal structures of LiSiGe for x = 2.3, 3.1, 3.5, and 4 as well as LiGe

Journal of the Chemical Society. Dalton Transactions, ISSN: 1477-9226, Vol: 43, Issue: 40, Page: 14959-14970
2014
  • 28
    Citations
  • 0
    Usage
  • 25
    Captures
  • 0
    Mentions
  • 0
    Social Media
Metric Options:   Counts1 Year3 Year

Metrics Details

  • Citations
    28
    • Citation Indexes
      28
  • Captures
    25

Article Description

A reinvestigation of the lithium-rich section of the Li–Ge phase diagram reveals the existence of two new phases, LiGe and LiGe (LiGe). Their structures are determined by X-ray diffraction experiments of large single crystals obtained from equilibrated melts with compositions LiGe and LiGe. Excess melt is subsequently removed through isothermal centrifugation at 400 °C and 530 °C, respectively. LiGe crystallizes in the space group F4 3m (a = 18.8521(3) Å, V = 6700.1(2) Å, Z = 20, T = 298 K) and LiGe (LiGe) in Cmcm (a = 4.5511(2) Å, b = 22.0862(7) Å, c = 13.2751(4) Å, V = 1334.37(8) Å, Z = 16, T = 123 K). Both phases are isotypic with their Si counterparts and are further representative of the LiPb and LiSi structure types. Additionally, the solid solutions LiSiGe follows Vegard's law. A comparison of the GeLi coordination polyhedra shows that isolated Ge atoms are 13- and 14-coordinated in LiGe, whereas in LiGe the Ge atoms possess coordination numbers 12 and 13. Regarding the thermodynamic stability, LiGe is assigned a high-temperature phase existing between ∼400 °C and 627 °C, whereas LiGe decomposes peritectically at 520–522 °C. Additionally, the decomposition of LiGe below ∼400 °C was found to be very sluggish. These findings are manifested by differential scanning calorimetry, long-term annealing experiments and the results from melt equilibration experiments. Interestingly, the thermodynamic properties of the lithium-rich tetrelides LiTt and LiTt (LiTt) are very similar (Tt = Si, Ge). Besides LiTt, LiTt, LiTt, and LiTt, the title compounds are further examples of isotypic tetrelides in the systems Li–Tt. © 2014 the Partner Organisations.

Provide Feedback

Have ideas for a new metric? Would you like to see something else here?Let us know