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Transport of potassium ions in niobium phosphate glasses
Author(s) -
Razum Marta,
Pavić Luka,
Ghussn Luciana,
MogušMilanković Andrea,
Šantić Ana
Publication year - 2021
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/jace.17882
Subject(s) - niobium , phosphate glass , potassium , ion , ionic conductivity , raman spectroscopy , materials science , potassium niobate , conductivity , phosphate , ionic bonding , glass transition , natural bond orbital , diffusion , inorganic chemistry , mineralogy , crystallography , analytical chemistry (journal) , chemistry , ferroelectricity , molecule , metallurgy , optics , thermodynamics , composite material , electrolyte , physics , optoelectronics , electrode , chromatography , dielectric , polymer , organic chemistry
The influence of Nb 2 O 5 on the structure and ionic conductivity of potassium phosphate glasses was investigated in glasses with composition x Nb 2 O 5 –(100‐ x )[0.45K 2 O–0.55P 2 O 5 ], x = 10–47 mol%. The Raman spectra of glasses reveal a transition from predominantly orthophosphate to predominantly niobate glass network with increasing Nb 2 O 5 content. In the glass structure, niobium forms NbO 6 octahedra which are interlinked with phosphate units for the glass containing 10 mol% Nb 2 O 5 , but for higher Nb 2 O 5 content they become mutually interconnected via Nb‐O‐Nb bonds. The transport of potassium ions was found to be strongly dependent on the structural characteristics of the glass network. While the mixed niobate‐phosphate glass network hinders the diffusion of potassium ions by providing traps that immobilize them and/or by blocking the conduction pathways, predominantly niobate glass network exhibits a rather facilitating effect which is evidenced in the trend of DC conductivity as well as in the features of the frequency‐dependent conductivity and typical hopping lengths of potassium ions.