Effect of Calcination Temperature and Holding Time on Crystal Structure and Size of Tetragonal ZrO2 Anugrah Rezki Akhmad, Adam Aswin Usman, Misdayanti,Linda Silvia,Suminar Pratapa, Fahmi Astuti
Departement of Physics, Faculty of Science and Data Analytics, Institut Teknologi Sepuluh Nopember, Surabaya, 60119, Indonesia
Abstract
This study investigates the synthesis of tetragonal zirconia (t-ZrO2) from natural zircon sand via alkali fusion, focusing on the effects of calcination temperature (800 C, 900 C, and 1000 C) and holding time (3, 5, 7, and 12 hours) on crystal structure and crystallite size. X-ray diffraction (XRD) analysis reveals that at 800 C, the lattice parameter a and unit cell volume initially decrease with increasing holding time, then increase, indicating a shift from stress relaxation and defect elimination to crystal growth and phase stabilization. In contrast, at 1000 C, both lattice parameter a and unit cell volume consistently decrease with longer holding times, reflecting enhanced atomic diffusion, reduction of oxygen vacancies, and stabilization of the tetragonal phase. Menawhile, crystallite size steadily increases with temperature and holding time, ranging from approximately 7 to 17 nm. These results indicate that holding time and temperature play crucial roles in the formation of t-ZrO2. Moreover, the crystallite size of t-ZrO2 increases nearly fourfold when the holding time is extended from 3 to 12 hours at 1000 C. The observed trends reflect the complex interaction between kinetic effects and thermodynamic stability in shaping the crystal structure and size evolution during alkali fusion synthesis.
