2010/08/31 by Vladimir Belostotsky, Belostotsky, Vladimir
Chemistry · Materials Science · Physics and Astronomy · #82C70 #Alkali metal #Alkaline earth metal #Chemical physics #Chemistry #Context (archaeology) #FOS: Physical sciences #Geology #Glass properties and applications #Glass transition #Inorganic chemistry #Ion #Ionic bonding #Ionic radius #J.2.9 #Materials Science (cond-mat.mtrl-sci) #Phase-change materials and chalcogenides #Polymer #Solid-state spectroscopy and crystallography #Ternary operation #acm:82C70 #cond-mat.mtrl-sci #msc:82C70
paper · pdf · doi:10.48550/arxiv.1009.0070
15 pages, 3 figures
openalex publication_date 2010/08/31 · arxiv created 2010/09/01 · arxiv updated 2010/09/02 · openalex created_date 2022/10/07 · openalex updated_date 2026/08/06
Peculiarities of mixed cation effect in ternary glasses whose composition\ninvolves alkali and non-alkali unicharged ions and/or alkaline earth ions are\nexplored within context of defect model for mixed mobile ion effect (V.\nBelostotsky, J. Non-Cryst. Solids (2007)). In mixed alkaline earth glasses\nmixed cation effect is observed as in ionic diffusivity as well as in the glass\ntransition temperature reflecting the fact that movement of dissimilar ions of\nunequal size is accompanied by formation of intrinsic defects in glass matrix\nwhen mobile ions enter foreign sites. It is qualitatively similar to that in\nmixed alkali glasses although quantitatively it is much less pronounced due to\nlower mobility of alkaline earth ions. In mixed cation glasses whose\ncomposition involves dissimilar mobile ions with ionic radii close to each\nother 'classical' mixed mobile ion effect is not observed in sense we face it\nin mixed alkali glasses. In alkali alkaline earth glasses like\nxNa2O-(1-x)CaO-SiO2 and xK2O-(1-x)BaO-SiO2 energy landscape is comprised of\nregular unicharged alkali sites and double-charged alkaline-earth sites, and\nmobile ions of both types can utilize either vacant sites without their\nrearrangement. This leads to increase in apparent diffusivity of alkaline-earth\nspecies when their concentration decreases which is opposite to what is\nreported for mixed alkali glasses. Mixed cation effect in the transition\ntemperature of such glasses is not observed which is clear indication that site\nrearrangement involving generation of intrinsic defects does not occur when a\nmobile ion enters a foreign site. Similar picture is observed in Na-Ag\nphosphate glasses where mixed cation effect in ionic conductivity is\nanomalously low because dissimilar ions have almost equal ionic radii and can\nutilize either vacant sites without their rearrangement and intrinsic defect\nformations in nearest glass matrix\n