title: Synthesis, luminescence properties and EPR investigation of hydrothermally derived uniform ZnO hexagonal rods.
abstract: One-dimensional (1D) zinc oxide (ZnO) hexagonal rods have been successfully synthesized by surfactant free hydrothermal process at different temperatures. It can be found that the reaction temperature play a crucial role in the formation of ZnO uniform hexagonal rods. The possible formation processes of 1-D ZnO hexagonal rods were investigated. The zinc hydroxide acts as the morphology-formative intermediate for the formation of ZnO nanorods. Upon excitation at 325 nm, the sample prepared at 180°C show several emission bands at 400 nm (∼3.10 eV), 420 nm (∼2.95 eV), 482 nm (∼2.57 eV) and 524 nm (∼2.36 eV) corresponding to different kind of defects. TL studies were carried out by pre-irradiating samples with γ-rays ranging from 1 to 7 kGy at room temperature. A well resolved glow peak at ∼354°C was recorded which can be ascribed to deep traps. Furthermore, the defects associated with surface states in ZnO nano-structures are characterized by electron paramagnetic resonance.
authors.affiliation: Department of Physics, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India. Electronic address: ajreddy09@gmail.com.
authors.forename: A Jagannatha
authors.initials: AJ
authors.lastname: Reddy
authors.affiliation: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India. Electronic address: rhk.chem@gmail.com.
authors.forename: R Hari
authors.initials: RH
authors.lastname: Krishna
authors.affiliation: Department of Chemistry, M.S. Ramaiah Institute of Technology, Bangalore 560 054, India.
authors.forename: B M
authors.initials: BM
authors.lastname: Nagabhushana
authors.affiliation: Department of Physics, Bangalore University, Bangalore 560 056, India.
authors.forename: M K
authors.initials: MK
authors.lastname: Kokila
authors.affiliation: Centre for Advanced Materials Research, Tumkur University, Tumkur 572 103, India.
authors.forename: H
authors.initials: H
authors.lastname: Nagabhushana
authors.affiliation: Solid State and Structural Chemistry Unit, Indian Institute of Science, Bangalore 560 012, India.
authors.forename: C
authors.initials: C
authors.lastname: Shivakumara
authors.affiliation: National Aerospace Laboratories (CSIR), Bangalore 560017, India.
authors.forename: R P S
authors.initials: RP
authors.lastname: Chakradhar
mesh_terms: D004578:Electron Spin Resonance Spectroscopy; D005720:Gamma Rays; D049449:Luminescence; D043942:Nanotubes / Q000737:chemistry* / Q000648:ultrastructure; D011208:Powders; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction; D015034:Zinc Oxide / Q000138:chemical synthesis* / Q000737:chemistry*
chemical_list: D011208:Powders; D014867:Water; D015034:Zinc Oxide
keywords: Electron paramagnetic resonance; Hexagonal rods; Hydrothermal; Photoluminescence; Thermoluminescence