Glass structure as a driver of polaronic conductivity in phosphate glasses containing MoO3 and WO3

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F23%3A39920373" target="_blank" >RIV/00216275:25310/23:39920373 - isvavai.cz</a>

Výsledek na webu

<a href="https://pubs.rsc.org/en/content/articlelanding/2023/tc/d3tc00954h" target="_blank" >https://pubs.rsc.org/en/content/articlelanding/2023/tc/d3tc00954h</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1039/d3tc00954h" target="_blank" >10.1039/d3tc00954h</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Glass structure as a driver of polaronic conductivity in phosphate glasses containing MoO3 and WO3

Popis výsledku v původním jazyce

Glasses containing transition metal (TM) oxides exhibit polaronic conductivity which, according to a well-accepted view, depends on the overall amount of TMO and the fraction of reduced TM ions. In this study we show that in phosphate glasses containing WO3 and MoO3, polaronic conductivity is entirely governed by the structural features of the glass network and cannot be correlated with these parameters. Tungsten glasses are found to exhibit six orders of magnitude higher conductivity than their molybdenum counterparts despite a significantly lower fraction of W5+ ions and the compositional change of DC conductivity is non-monotonic in both glass systems. We relate the former effect to the tendency of WO6 units to aggregate by forming W-O-W-O-W bonds which facilitate polaronic transport, in contrast to MoO6 and MoO4 units which are prone to incorporate into a phosphate network uniformly thus failing to provide such fast conduction pathways. More interestingly, we show that the latter effect originates from the manner in which tungstate or molybdate units are mutually linked within the phosphate network: if they form chains with a sufficient number of flexible terminal oxygen bonds (lower TMO content) polaronic transport is facilitated whereas if they connect three-dimensionally, causing a reduction in the number of terminal oxygens (higher TMO content), conductivity is hindered. A detailed analysis of frequency-dependent conductivity and permittivity using the MIGRATION concept helps us understand the structural features that influence conductivity in these glasses and points out the importance of network connectivity in the propagation of polarons on long-range and localized scales.

Název v anglickém jazyce

Glass structure as a driver of polaronic conductivity in phosphate glasses containing MoO3 and WO3

Popis výsledku anglicky

Glasses containing transition metal (TM) oxides exhibit polaronic conductivity which, according to a well-accepted view, depends on the overall amount of TMO and the fraction of reduced TM ions. In this study we show that in phosphate glasses containing WO3 and MoO3, polaronic conductivity is entirely governed by the structural features of the glass network and cannot be correlated with these parameters. Tungsten glasses are found to exhibit six orders of magnitude higher conductivity than their molybdenum counterparts despite a significantly lower fraction of W5+ ions and the compositional change of DC conductivity is non-monotonic in both glass systems. We relate the former effect to the tendency of WO6 units to aggregate by forming W-O-W-O-W bonds which facilitate polaronic transport, in contrast to MoO6 and MoO4 units which are prone to incorporate into a phosphate network uniformly thus failing to provide such fast conduction pathways. More interestingly, we show that the latter effect originates from the manner in which tungstate or molybdate units are mutually linked within the phosphate network: if they form chains with a sufficient number of flexible terminal oxygen bonds (lower TMO content) polaronic transport is facilitated whereas if they connect three-dimensionally, causing a reduction in the number of terminal oxygens (higher TMO content), conductivity is hindered. A detailed analysis of frequency-dependent conductivity and permittivity using the MIGRATION concept helps us understand the structural features that influence conductivity in these glasses and points out the importance of network connectivity in the propagation of polarons on long-range and localized scales.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2023

Kód důvěrnosti údajů

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

Název periodika

Journal of Materials Chemistry C

ISSN

2050-7526

e-ISSN

2050-7534

Svazek periodika

11

Číslo periodika v rámci svazku

28

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

9628-9639

Kód UT WoS článku

001016300000001

EID výsledku v databázi Scopus

2-s2.0-85164391769