Cobalt in Co-Zn metaphosphate and pyrophosphate glasses: Structure , coordination and thermal properties

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F25%3A39923127" target="_blank" >RIV/00216275:25310/25:39923127 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.1016/j.jnoncrysol.2025.123782" target="_blank" >https://doi.org/10.1016/j.jnoncrysol.2025.123782</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnoncrysol.2025.123782" target="_blank" >10.1016/j.jnoncrysol.2025.123782</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Cobalt in Co-Zn metaphosphate and pyrophosphate glasses: Structure , coordination and thermal properties

Popis výsledku v původním jazyce

The interaction of cobalt in a wide compositional range was studied in Co-Zn phosphate glasses. Metaphosphate glasses xCoO-(50-x)ZnO-50P2O5, i.e. glasses with the same anion, and glasses in which the anion simultaneously changes from metaphosphate to pyrophosphate with increasing cobalt concentration, meta-pyro series, yCoO-(50-0.75y)ZnO-(50-0.25y)P2O5, were prepared. XRF, Raman spectra and 31P MAS NMR confirmed the desired chemical composition of all the prepared glasses. The electronic spectra demonstrated both the tetrahedral and octahedral coordination of the Co(+II). The combination with Raman spectroscopy showed a predominant tetrahedral coordination. A simple chemical model of meta-pyro series was proposed. The Co-O(P) bond was found to be considerably polar, thereby increasing the density of weak interactions in the glass network, which in turn caused an increase in Tg with increasing Co content in both series. It was determined that the coefficient of thermal expansion increases with rising cobalt concentration. This is related to the assumption of a higher amplitude of vibrations of the Co-O(P) bond compared to the Zn-O(P) bond, indicating the increasing asymmetry of the Morse potential. The compositional dependence of density and molar volume indicates the increasing compactness of the glass structure with increasing cobalt content.

Název v anglickém jazyce

Cobalt in Co-Zn metaphosphate and pyrophosphate glasses: Structure , coordination and thermal properties

Popis výsledku anglicky

The interaction of cobalt in a wide compositional range was studied in Co-Zn phosphate glasses. Metaphosphate glasses xCoO-(50-x)ZnO-50P2O5, i.e. glasses with the same anion, and glasses in which the anion simultaneously changes from metaphosphate to pyrophosphate with increasing cobalt concentration, meta-pyro series, yCoO-(50-0.75y)ZnO-(50-0.25y)P2O5, were prepared. XRF, Raman spectra and 31P MAS NMR confirmed the desired chemical composition of all the prepared glasses. The electronic spectra demonstrated both the tetrahedral and octahedral coordination of the Co(+II). The combination with Raman spectroscopy showed a predominant tetrahedral coordination. A simple chemical model of meta-pyro series was proposed. The Co-O(P) bond was found to be considerably polar, thereby increasing the density of weak interactions in the glass network, which in turn caused an increase in Tg with increasing Co content in both series. It was determined that the coefficient of thermal expansion increases with rising cobalt concentration. This is related to the assumption of a higher amplitude of vibrations of the Co-O(P) bond compared to the Zn-O(P) bond, indicating the increasing asymmetry of the Morse potential. The compositional dependence of density and molar volume indicates the increasing compactness of the glass structure with increasing cobalt content.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10402 - Inorganic and nuclear chemistry

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Non-Crystalline Solids

ISSN

0022-3093

e-ISSN

1873-4812

Svazek periodika

668

Číslo periodika v rámci svazku

November 2025

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

11

Strana od-do

123782

Kód UT WoS článku

001577811100002

EID výsledku v databázi Scopus

2-s2.0-105016316531