Raman, FTIR studies and optical absorption of zinc borate glasses containing WO 3

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Raman, FTIR studies and optical absorption of zinc borate glasses containing ­WO3 M. Farouk1 · A. Samir2 · A. Ibrahim3 · M. A. Farag1 · A. Solieman4 Received: 10 June 2020 / Accepted: 5 August 2020 © Springer-Verlag GmbH Germany, part of Springer Nature 2020

Abstract Glasses with composition [xWO3–(25−x)–ZnO–20Na2O–55B2O3 where x = 0, 5, 10, 15 and 20 mol. %] were prepared by melt quenching method. The amorphous state of the current glass samples was checked by X-ray diffraction (XRD). The measured density and calculated molar volume of all prepared samples were found to increase with the replacement of the lighter ZnO by the heavier of W ­ O3. The network structure of the present glasses was studied using the infrared (IR) and Raman spectroscopic techniques. IR and Raman results show that the structure of the samples is ­BO3 and ­BO4 units located in several structural groups with W–O–W units. The decreasing of the band gap energy values by the introducing of ­WO3 showed that the creation increases of the number of non-bridging oxygens in the structure of glass. All results showed that the parameters were dependent upon the dopant concentration of ­WO3 in the prepared glasses. Keywords  Infrared · Raman · Optical · Structure · WO3 · Borate glass

1 Introduction Glass systems containing tungsten ions have a great interest because of their unique thermal, electrical and optical properties such as photochromism for important applications, which are known for a color change because of the movement of electromagnetic radiation [1–10]. Because of this reason, the type of this glass is useful for applications in photonic devices of a large memory, smart windows to control solar input of semiconductor houses [11, 12]. These properties depend on the existence of tungsten in several valance states such as ­W6+, ­W5+ and ­W4+ [12, 13]. The tungsten ­W6+ ions take part in the glass network with various structural groups as W ­ O4 tetrahedral and W ­ O6 * M. Farouk [email protected]; [email protected] 1



Physics Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo 11884, Egypt

2



Engineering Mathematics and Physics Department, Faculty of Engineering at Shoubra, Benha University, Cairo 11629, Egypt

3

Basic Sciences Department, Faculty of Engineering Science, Sinai University, El Kantara, Egypt

4

Physics Department, Faculty of Science, Al-Azhar University, Assuit branch, Cairo, Egypt



octahedral. On the other hand, W ­ 5+ ions (­ 5d1 are known paramagnetic ions) participate in the shape of ­W5+O3− and occupy octahedral (­ Oh) positions [12, 14, 15]. Therefore, the existence of tungsten ions in many oxidation states and structural units in the glass system at a given temperature depends on the modifiers, formers, mobility of the modifier cation [12, 16–18]. Borate glass exhibit importance materials for engineering technology because of their low melting point (Tm), high transparency, thermal stability, good glass former, easy to process, nontoxic, high density, shielding for IR radiations