Research Article Fabrication and Crystallization of ZnO-SLS Glass Derived Willemite Glass-Ceramics as a Potential Material for Optics Applications Mohd Hafiz Mohd Zaid, 1 Khamirul Amin Matori, 1,2 Sidek Hj. Abdul Aziz, 1 Halimah Mohamed Kamari, 1 Wan Mahmood Mat Yunus, 1 Zaidan Abdul Wahab, 1 and Nur Farhana Samsudin 2 1 Department of Physics, Faculty of Science, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia 2 Materials Synthesis and Characterization Laboratory, Institute of Advanced Technology, Universiti Putra Malaysia (UPM), 43400 Serdang, Selangor, Malaysia Correspondence should be addressed to Khamirul Amin Matori; khamirul@upm.edu.my Received 29 October 2015; Revised 3 January 2016; Accepted 6 January 2016 Academic Editor: Austin Nevin Copyright © 2016 Mohd Hafz Mohd Zaid et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Willemite glass-ceramics were successfully derived from conventional melt-quench ZnO-SLS precursor glass by an isothermal heat treatment process. Te efect of heat treatment temperatures on the physical properties was investigated by Archimedes principle and linear shrinkage. Te generation of willemite crystal phase and morphology with increase in heat treatment temperature was examined by X-ray difraction (XRD), Fourier transform infrared (FTIR), and feld emission scanning electron microscopy (FESEM) techniques. X-ray difraction revealed that the metastable -Zn 2 SiO 4 and thermodynamically stable zinc orthosilicate - Zn 2 SiO 4 phases can be observed at temperatures above 700 ∘ C. Te experimental results indicated that the density and shrinkage of the glass-ceramic vary with increasing the sintering temperature. FTIR studies showed that the structure of glass-ceramic consists of SiO 2 and ZnO 4 units and exhibits the structural evolution of willemite glass-ceramics. Te characteristic of strong vibrational bands can be related to the [SiO 4 ] 4− tetrahedron corresponding to reference spectra of willemite. 1. Introduction Recently, manufacturing industries played an important role in economic growth. However, this rapid industrialization generates enormous amount of waste such as glass waste which necessitates diferent attitudes toward solid waste management [1]. Terefore, converting these solid wastes into more valuable and environment friendly products is a new focus across the world. Tis is in line with the increasing demand for limited natural resources; hence waste recovery provides alternative resources which reduces dependency on natural resource such as sand-silica for production of glasses [2] and glass-ceramics [3, 4]. Among silica-rich wastes, soda lime silica (SLS) glass from bottle banks has attracted much attention. SLS glass from urban waste consists mainly of silicon (SiO 2 ), sodium (Na 2 O), and calcium oxides (CaO). Tanks to its potential of low temperature viscous fow sintering, SLS glass can be considered as a good candidate for total, or partial, replacement of the natural fuxes [5–7]. Glass- ceramics possess many favorable properties including low density, low thermal conductivity, high surface area, virtuous thermal shock resistance, and great specifc strength [8]. Glass-ceramic containing willemite (Zn 2 SiO 4 ) has been known, for many years, as materials for electronic applica- tions and has been identifed as a suitable host matrix for many rare earth and transition metal dopant ions for efcient luminescence [9–14]. Willemite is one of the zinc ore minerals having the phenakite structure. In Zn 2 SiO 4 , all the atoms occupy general position and are composed of tetrahedral framework where zinc and silicon are positioned in three diferent fourfold crystallographic sites: two slightly diferent zinc sites Zn 1 (⟨Zn-O⟩ 1.950 ˚ A) and Zn 2 (⟨Zn-O⟩ 1.961 ˚ A), and Si (⟨Si-O⟩ 1.635 ˚ A), thus resulting in rhombohedra symmetry with lattice parameters  =  ∼ 13.948 ˚ A and Hindawi Publishing Corporation Journal of Spectroscopy Volume 2016, Article ID 8084301, 7 pages http://dx.doi.org/10.1155/2016/8084301