The cubic structure of Li 3 As stabilized by substitution - Li 8 TtAs 4 (Tt = Si, Ge) and Li 14 TtAs 6 (Tt = Si, Ge, Sn) and their lithium ion conductivity

• Published in: Dalton transactions : an international journal of inorganic chemistry 2024-07, Vol.53 (27), p.11257-11263
• Main Authors: Schmid, Martin, Wegner, Florian, De Giorgi, Claudia, Pielnhofer, Florian, Pfitzner, Arno
• Format: Article
• Language: English
• ISSN: 1477-9226; 1477-9234
• DOI: 10.1039/d4dt00664j

The new lithium arsenidotetrelates Li SiAs , Li GeAs , Li SiAs , Li GeAs and Li SnAs were synthesized ball milling and structurally characterized by Rietveld analysis of X-ray powder diffraction data. The aliovalent substitution of lithium in hexagonal Li As by introducing a tetravalent tetrel cation stabilizes cubic structures for Li TtAs (Tt = Si, Ge) in the space group 3̄ and for the lithium richer compound Li TtAs (Tt = Si, Ge, Sn) in the higher symmetrical space group 3̄ (no. 225). Thermal properties of the arsenidotetrelates were investigated high temperature powder diffraction and differential thermal analysis revealing a decomposition process of the lithium richer arsenidotetrelate (Li TtAs → Li TtAs + 2Li As) into the lithium poorer arsenidotetrelates and lithium arsenide at moderate temperatures. Impedance spectroscopy shows moderate to good lithium ion conductivity for the lithium arsenidotetrelates.