Nano Express

Nanoscale Research Letters

, Volume 4, Issue 11, pp 1371-1379

Open Access This content is freely available online to anyone, anywhere at any time.

Morphology and Photoluminescence of HfO2 Obtained by Microwave-Hydrothermal

  • S. A. EliziárioAffiliated withIQ-LIEC, Universidade Estadual Paulista
  • , L. S. CavalcanteAffiliated withLIEC, Departamento de Química e Física, Universidade Federal de São Carlos
  • , J. C. SczancoskiAffiliated withLIEC, Departamento de Química e Física, Universidade Federal de São Carlos Email author 
  • , P. S. PizaniAffiliated withLIEC, Departamento de Química e Física, Universidade Federal de São Carlos
  • , J. A. VarelaAffiliated withIQ-LIEC, Universidade Estadual Paulista
  • , J. W. M. EspinosaAffiliated withIQ-LIEC, Universidade Estadual Paulista
  • , E. LongoAffiliated withIQ-LIEC, Universidade Estadual Paulista

Abstract

In this letter, we report on the obtention of hafnium oxide (HfO2) nanostructures by the microwave-hydrothermal method. These nanostructures were analyzed by X-ray diffraction (XRD), field-emission gum scanning electron microscopy (FEG-SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectrometry (EDXS), ultraviolet–visible (UV–vis) spectroscopy, and photoluminescence (PL) measurements. XRD patterns confirmed that this material crystallizes in a monoclinic structure. FEG-SEM and TEM micrographs indicated that the rice-like morphologies were formed due to an increase in the effective collisions between the nanoparticles during the MH processing. The EDXS spectrum was used to verify the chemical compositional of this oxide. UV–vis spectrum revealed that this material have an indirect optical band gap. When excited with 488 nm wavelength at room temperature, the HfO2 nanostructures exhibited only one broad PL band with a maximum at around 548 nm (green emission).

Keywords

HfO2 Nanoparticles Morphology Optical band gap Photoluminescence