Preparation, crystallization and photoluminescence properties of un-doped nano willemite glass ceramics with high ZnO additions

• Published in: Optik (Stuttgart) 2020-03, Vol.206, p.164374, Article 164374
• Main Authors: Abdel-Hameed, Salwa A.M., Margha, Fatma H.
• Format: Article
• Language: English
• Subjects: Gahnite; Glass-ceramic; Hoppered crystals; Photoluminescence; White emission; β- and α-Willemite
• ISSN: 0030-4026; 1618-1336
• DOI: 10.1016/j.ijleo.2020.164374

Fabrication and crystallization behavior of glasses in the system ZnO.B2O3.SiO2.Al2O3 were studied via melt–quenching method; ZnO/SiO2 ratio was changed from 5.4 to 1.4. Heat treatments, according to Differential Scanning Calorimetric (DSC) beside 1050 °C/2 h were done to study the effect of temperature on the development and stability of the crystallized phases and microstructure. Nano crystallite α-Willemite was detected by X-ray diffraction analysis (XRD). The decrease in the crystallite size was enhanced with decrease ZnO/SiO2 ratio under fixed heat treatment temperature; while increase in crystallite size in the same composition with increasing heat treatment temperature was observed. The sequence of crystallization started with Zn3(BO3)2, then β-willemite (Zn2SiO4) which converted to α-willemite with increasing temperature; traces of gahnite (ZnAl2O4) was appeared at 1050 °C/2 h. Photoluminescence revealed bluish white emission with different intensity after exposing to λex = 254 nm; so the prepared material can nominate to optical applications such as light emitting and laser diodes.