Microwave assisted synthesis of cubic Zirconia nanoparticles and study of optical and photoluminescence properties

Synthesis of pure ZrO2 nanoparticles in its cubic phase is a challenging task for the researchers. ZrO2 is a promising material and has received considerable attention recently due to superior properties that provide significant advantages in various applications like display systems and lighting. This paper discusses a better method of synthesis of pure ZrO2 nano crystals in cubic phase, free from impurities that alter the luminescence emissions. Studies on structural, optical and photoluminescence properties are reported. The structural studies show that as formed ZrO2 nanoparticles are in cubic phase. The crystallinity and phase formation of the samples were studied by XRD, the crystallinity increases as the calcination temperature increases. The samples are mesoporous and pore size decreases with increase in the calcination temperature as studied by BET. The optical energy band gap (Eg) was calculated and found to be 5.21 eV for the as formed sample. As calcination temperature increases the increase in the optical band gap is observed. The PL spectra show an intense violet emission band peak centered at 387 nm, due to the presence of the oxygen vacancies in the ZrO2 matrix. The crystallinity, particle size and the phase formation was further confirmed by HRTEM.