Effect of BO 4 and FeO 4 Structural Units on Conduction Mechanism of Iron Borosilicate Glasses
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ORIGINAL PAPER
Effect of BO4 and FeO4 Structural Units on Conduction Mechanism of Iron Borosilicate Glasses G. El-Damrawi 1
&
A. M. Abdelghany 2 & A. K. Hassan 1 & B. Faroun 1
Received: 30 April 2020 / Accepted: 5 September 2020 # Springer Nature B.V. 2020
Abstract Several oxide glasses in the xFe2O3.25SiO2.(43-x)B2O3.30Na2O.2Al2O3 system were synthesized by the melt quenching technique. The effect of changing concentration of both BO4 and FeO4 tetrahedral building units on conductivity behavior has been studied. Fourier transforms infrared (FTIR) spectroscopy was used to shed more insight into the iron ions’ structural role in borosilicate glasses. The two valance states of iron ions (Fe2+ and Fe3+) were detected by EDAX spectra. The conductivity and associated activation energy were found to be affected by changing B4 (BO4 and FeO4) concentrations. The conductivity increases and the corresponding activation energy decreases as the B4 fraction increases. The concentration of tetrahedral (BO4) units decreases and of (FeO4) is increased with increasing FeO2. Increasing the concentration of FeO4 is assumed as the main reason for conductivity improvements. Keywords Glass structure . Electronic conduction . Fraction of BO4 . Iron oxide . SEM . FTIR
1 Introduction Oxide Glasses as well as chalcogenide glasses which contain transition metals are considered between the most commercial and scientific importance in the field of applications [1–3]. For example, several compositional variations from borosilicate glasses [4, 5] have been previously applied as special sealants. The technical benefits of modified borosilicate glasses are mainly associated with the structural arrangement of the network constituents of the glass. Some of the spectroscopic tools such as FTIR and NMR techniques are the most effective tool used to examine and organize the silicate and borate building units [6, 7]. Transition metal oxides such as Fe2O3, CeO2, CuO, and V2O5 can add more advantages to the properties and structure of the investigating glasses. They usually characterized the transfer of octahedral and tetrahedral sites by their spin-allowed transitions [8, 9]. These features make the glass as a potential material in a wide range of applications. In this regard, the material can enter in the manufacture of light-emitting diodes, like spin glasses and
ground emission displays. Silicate-based [6–8], phosphate-based [9], and borate-based [10, 11] glasses are considered as the most reported hosts for dissolving Fe2O3. In contrast, to our knowledge, researches on the broad content of Fe2O3 in borosilicate glasses are limited. It was reported previously (by Raman, Mössbuer, and XANES spectroscopy) that Fe2+ oxygen coordination changes between four-fold and six-fold. The Fe3+ is former primarily in the tetrahedral coordination network. The tetrahedral boron fraction is based on both the iron fraction and the redox state [11]. The electrical properties of iron oxide-containing sodium borosilicate glasses have been recently studied [12]. On
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