[01] Gomaa-El Damrawi, Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt. [02] Naer Baker, Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt. [03] Ahamed Al-kalbani, Physics Department, Faculty of Science, Mansoura University, Mansoura, Egypt.

The phase change and micro-structure determination of both ZnO and ZnO-Al₂O₃ matrices have been investigated using nuclear magnetic resonance spectroscopy (NMR), X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDS) and transition electron microscopy (TEM) with selected area electron diffraction (SAED). The effect of both material structure and thermal heat treatment (THT) at different temperatures on the crystallization nature of ZnO and Al₂O₃-ZnO nanoparticles was recorded. A well-controlled crystallization extraction was followed by crystalline phase formation. The matrix structure of ZnO-Al₂O₃ is completely changed by partially replacing ZnO with Al₂O₃. It is confirmed that the quantity and type of crystalline ZnO phases are affected by changing glass structure and heat treatment temperature. The crystalline structure in the ZnO matrix is fully transformed into an amorphous one by introducing Al₂O₃ to ZnO. This finding was due to the development of the material structure through non-bridging bonds (NBB). The NBB formation can reduce the unified and symmetrical structure leading to the formation of the less orderly network. On the other hand, the amorphous phases are converted into the crystalline (ZnAl₂O₄) one, especially in heat-treated ZnO-Al₂O₃ glasses. This is because the THT mechanism will allow the process of phase separation that leads to crystallization to take place. The structure and size of various crystals can be identified by TEM microscopy. The ²⁷AlNMR analysis showed a considerable change in chemical shift upon increasing Al₂O₃. Sample containing 1 w% Al₂O₃ contains defective AlO₄ units. While sample containing 5 w% Al₂O₃ has a more shielded structure due to formation of strengthened Al₄-O-Zn₄ bonds

Zinc Nanoparticles, Heat Treatment, Amorphous Phase, Phase Separation, NMR Spectroscopy

[01] J. Zhang, W. Que, Y. Yuan, P., Zhong., andY. Liao. Preparation of Al-doped ZnO nanocrystalline aggregates with enhanced performance for dyeadsorption, Science China Physics. Mechanical and Astromomy 55 (7) (2012) 1198-1202 [02] N. Shanmugam, S. Suthakaran, N. Kannadasan, and K. Sathishkumar, Synthesis and characterization of Te doped ZnO nanosheets for photocatalyric applications. JO Heterocyclics 105 (2015) 15-20 [03] K. S. Khashan, and M. Mhdi, Preparation of Indium-Doped zinc oxide nanoparticles by pulsed laser ablation in liquid technique and therir characterization. Applied Nanoscience 7 (8) (2017) 589-596. [04] K. J Chen. T. H Fang, F. Y. Hung, L. W. Ji, S. J Chang. S. J Young,, and Y. I Hsiao, The crystallization and physical properties of Al-doped ZnO nanoparticles. Applied surface Science, 254 (18) (2008) 5791-5795. [05] Y. Fujimoto, M. Nakatsuka, ²⁷Al NMR structural study on aluminum coordination state in bismuth doped silica glass, Journal of Non-Crystalline Solids 352 (2006) 2254–2258 [06] S. H. Risbud, R. J. Kirkpatrick, A. P. Taglialavore, B. Montez, J. Am. Ceram. Soc. 70 (1987) 10 [07] M. Schmiicker, K. J. D. MacKenzie, H. Schneider, R. Meinhold, J. Non-Cryst. Solids 217 (1997) 99. [08] G. El-Damrawi, A. K. Hassan, A. Shahboub, ³¹P and ²⁷Al nuclear magnetic resonance studies on silver phosphate glasses, Magn. Reson. Solids 20 (2018), 18202. [09] L. Balua, R. Amaravel, and R. Ezhil Pavaib, Effect of Zno on Physical, Structural and Mechanical Properties of B₂O₃-Na₂O-ZnO glasses, IOSR Journal of Applied Physics (IOSR-JAP) e-ISSN: 2278-4861. Volume 8, Issue 6. -Dec. (2016) 140-146 [10] H. S. Liu and T. S. Chin, “The new zinc barium metaphosphate glasses. (50-x) BaO-xZnO-50P₂O₅” Physics and Chemistry of Glasses, 38 (1997) 123–131. [11] K. A. Matori, M. H. M. Zaid, H. A. A. Sidek, M. K. Halimah, Z. A. Wahab, and M. G. M. Sabri, “Influence of ZnO on the ultrasonic velocity and elastic moduli of soda lime silicate glasses,” International Journal of Physical Sciences, 5 (2010) 2212–2216 [12] M. Malini, M. Thirumavalavan, W. Y. Yang, J. F. Lee, G. Annadurai, A versatile chitosan/ZnO nanocomposite with enhanced antimicrobial properties, Int. J. Biol. Macromol. 80 (2015) 121–129. [13] M. Karpuraranjith, S. Thambidurai, Chitosan/zinc oxide-polyvinylpyrrolidone (CS/ZnO- PVP) nanocomposite for better thermal and antibacterial activity, Int. J. Biol. Macromol. 104 (2017) 1753–1761. [14] JA Johnson, JKR Weber, AI Kolesnikov, and S Schweizer, Crystallization in heat- treated fluorochlorozirconate glasses, J Phys Condens Matter. 16; 21 (37) (2009) 3751031–3751036. [15] S. Dalal, S. Khasa, M. S. Dahiya, ArtiYadav, A. Agarwal, S. Dahiya, Journal of Asian Ceramic Societies 3 (2015) 234-239. [16] M. -K. Song, M-Y. Lee, J-H. Seo, M, H. Kim, and S. Y. Yang, Journal of Nanomaterials Volume Article ID 151532 (2015) 6.