Structural Characterization and computational approach to doped hafnium oxide nano crystals for thermo and photoluminescence applications

Abstract

ABSTRACTDoped hafnium oxide (X-HfO2, X= Eu, Tb, Dy) thin films were deposited by experimental ultrasonic spray pyrolysis process. Doped Hf nano crystal (nc-X-Hf) embebed in the HfO2 matrix were obtained. The process was made at substrate temperature between 300 °C and 550 °C, showing at this higher temperature the monoclinic phase, which improve the dopants incorporation. Computational simulations were made to analyze molecular dynamics in advance to improve physical and chemical properties. Energy relaxation, and charge distribution behaviour demonstrated an atomic re-arranged to form the nano clusters of 5nm to 10 nm diameter. Vibrational modes were calculated. Photoluminescence (PL) spectra were obtained, as dopant function. Atomic Force Microscopy (AFM), X-ray diffraction and High Resolution Transmission Electron Microscopy (HRTEM) characterizations were made. Characteristics bright peaks appear in the Thermoluminescence (TL) spectra, and PL peak emission as well, of the Eu, Tb, Dy dopants in the HfO2 matrix. The results obtained show that nanocrystal structures embebed in a metal oxide matrix of HfO2 could be a prominent material to be used in radiation dosimetry, technological development, and radiological protection.