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Electrochemical Studies in Glass: III, The System CoO‐Na 2 Si 2 O 5 *
Author(s) -
LACY ALTON M.,
PASK JOSEPH A.
Publication year - 1971
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1971.tb12279.x
Subject(s) - solubility , non blocking i/o , electrochemistry , phase diagram , electrolyte , oxide , analytical chemistry (journal) , phase (matter) , materials science , chemistry , inorganic chemistry , metallurgy , electrode , biochemistry , organic chemistry , chromatography , catalysis
A solid electrolyte electrochemical cell of the type Pt|Ni: NiO a=1 ‖ZrO 2 +7.5% CaO‖Co:CoO a<1 +Na 2 Si 2 O 5 glass|Pt was used to measure the activities of cobaltous oxide in Na 2 Si 2 O 5 , glass from 700° to 1100°C. From the variation in CoO activity, the activity of NS 2 glass in solution was calculated. Partial molar free energies and entropies of solution and free energies and entropies of mixing of these components were calculated from activity data. A partial phase diagram for the CoO‐Na 2 Si 2 o 5 system is proposed from the solubility data of this study. The solubility of CoO in Na 2 Si 2 O 5 glass varies from 44 to 52 mol% (∼24 to 31 wt%) over this temperature range. Comparison of partial molar entropies of Fe 0.95 O, CoO, and NiO in glass solution suggests that the structure is basically the same for a given O/Si ratio. Solubility limits are determined by the relative strengths of the –cation–O–cation– and –Si–O–cation‐bond assemblages.