Electrical transport and dielectric relaxation in 5Fe2O3-40ZnO-55P2O5 iron zinc phosphate bulk glass

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216275%3A25310%2F25%3A39922211" target="_blank" >RIV/00216275:25310/25:39922211 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0022309324004873" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0022309324004873</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jnoncrysol.2024.123311" target="_blank" >10.1016/j.jnoncrysol.2024.123311</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Electrical transport and dielectric relaxation in 5Fe2O3-40ZnO-55P2O5 iron zinc phosphate bulk glass

Popis výsledku v původním jazyce

Electrical Impedance Spectroscopy (EIS) and Optical Spectroscopy (OS) experimental techniques have been used to investigate some basic and important aspects of the electronic band structure, electrical transport and dielectric relaxation in 5Fe2O3–40ZnO–55P2O5 iron zinc phosphate bulk glass. The temperature dependence of the dc electrical conductivity, as determined by EIS, showed a simple Arhenius behaviour, with activation energy of ~1 eV, a value shared by a large number of other glassy systems. The EIS measurements revealed also a number of discrete dielectric relaxation processes, some of them possessing a non-exponential “universal” behaviour. The temperature dependence of the characteristic frequency of one of these dielectric relaxation processes was found to be related to the observed values of dc electrical conductivity at the same temperatures through Barton-Namikawa-Nakajima (BNN) relation. Based on the analysis of both the optical and the electrical measurements, it is concluded that the dc electrical transport is due to hole small polaron hopping, but the Fe sites are not the hopping sites. Rather, the added Fe atoms in their possible different charge states within theglassy matrix act as strongly localised acceptor sites (bands) and the dc electrical transport then takes place via self-trapped holes, originating from the remaining singly occupied electron states (holes) at the top of the valence band tails in studied glass. The existence of “defect” acceptor bands in the vicinity of the valence bands in wider band gap glassy materials and subsequent hole self-trapping is proposed to be a general trend and the cause of largely p-type behaviour and polaronic type of electrical conduction in these systems.

Název v anglickém jazyce

Electrical transport and dielectric relaxation in 5Fe2O3-40ZnO-55P2O5 iron zinc phosphate bulk glass

Popis výsledku anglicky

Electrical Impedance Spectroscopy (EIS) and Optical Spectroscopy (OS) experimental techniques have been used to investigate some basic and important aspects of the electronic band structure, electrical transport and dielectric relaxation in 5Fe2O3–40ZnO–55P2O5 iron zinc phosphate bulk glass. The temperature dependence of the dc electrical conductivity, as determined by EIS, showed a simple Arhenius behaviour, with activation energy of ~1 eV, a value shared by a large number of other glassy systems. The EIS measurements revealed also a number of discrete dielectric relaxation processes, some of them possessing a non-exponential “universal” behaviour. The temperature dependence of the characteristic frequency of one of these dielectric relaxation processes was found to be related to the observed values of dc electrical conductivity at the same temperatures through Barton-Namikawa-Nakajima (BNN) relation. Based on the analysis of both the optical and the electrical measurements, it is concluded that the dc electrical transport is due to hole small polaron hopping, but the Fe sites are not the hopping sites. Rather, the added Fe atoms in their possible different charge states within theglassy matrix act as strongly localised acceptor sites (bands) and the dc electrical transport then takes place via self-trapped holes, originating from the remaining singly occupied electron states (holes) at the top of the valence band tails in studied glass. The existence of “defect” acceptor bands in the vicinity of the valence bands in wider band gap glassy materials and subsequent hole self-trapping is proposed to be a general trend and the cause of largely p-type behaviour and polaronic type of electrical conduction in these systems.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20500 - Materials engineering

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

648

Číslo periodika v rámci svazku

January 2025

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

16

Strana od-do

123311

Kód UT WoS článku

001443746200001

EID výsledku v databázi Scopus

2-s2.0-85209569906