M Hadadian - Ph.D. candidate Ferdowsi University of Mashhad-Department of Chemistry, FerdowsiUniversity of Mashhad
E. K Goharshadi - Proffesor Ferdowsi University of Mashhad-Department of Chemistry, FerdowsiUniversity of Mashhad
Abbas Youssefi - Ph.D. Par-e-Tavous Research Institute-Par-e-Tavous Research Institute, Mashhad

Among advanced ceramics, zirconia is attracting increasing interest due to its excellentchemical resistance, good mechanical strength, high fracture toughness and hardness, highcoefficient of thermal expansion, low thermal conductivity together with relatively highcoefficient of thermal expansion, resistance to thermal shock, and wide band gap. In this work,zirconia nanoparticles with average particle size of ۲۷ nm were prepared by a facile, rapid, andcost-effective microwave-assisted method using zirconyl nitrate as the starting material. Thesynthesized nanoparticles were calcined at temperatures ranging from ۱۰۰ ˚C to ۶۰۰ ˚C. Thesamples were characterized by X-ray powder diffraction, transmission electron microscope, andUltraviolet-visible absorption spectroscopy. The band gap energy of zirconia samples wasfound to be ۵.۵ eV. The effect of calcination temperature on the structural and optical propertiesof zirconia nanoparticles was investigated as well. The results clearly showed the presence ofpurely monoclinic phase of zirconia when the calcination temperature exceeds ۴۰۰ ˚C.

Zirconia, calcination, microwave-assisted method, band gap