Open AccessSol–gel synthesis of Ba‐doped ZnO nanoparticles and its use in varistor ceramics
Author(s) -
Yang Rong,
Qu Xiao,
Wang MaoHua
Publication year - 2018
Publication title -
micro and nano letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.25
H-Index - 31
ISSN - 1750-0443
DOI - 10.1049/mnl.2018.0150
Subject(s) - materials science , sol gel , scanning electron microscope , analytical chemistry (journal) , transmission electron microscopy , doping , nanoparticle , sintering , hexagonal phase , energy dispersive x ray spectroscopy , lattice constant , varistor , ceramic , diffraction , nanotechnology , crystallography , hexagonal crystal system , composite material , optoelectronics , optics , chemistry , voltage , chromatography , physics , quantum mechanics
Un‐doped and Ba‐doped ZnO nanoparticles (Zn 1− x Ba x O 0 wt% ≤ x ≤4 wt%) were prepared by the sol–gel method and annealed at 500°C for 4 h under air atmosphere. Several techniques such as X‐ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive X‐ray spectroscopy and scanning electron microscopy were used to characterise the as‐prepared samples. The samples exhibited hexagonal ZnO lattice structure and a secondary phase of BaO is evolved for the sample with x = 0.02 and 0.04. The calculated average crystalline size decreases from 38.27 to 33.74 nm for x = 0 to 0.02 then reaches 39.93 nm for x = 0.04 which is confirmed by TEM. The change in micro‐strain and a small shift in XRD peaks reveal the substitution of Ba 2+ ions into the ZnO lattice. Additionally, using Ba‐doped ZnO powders via this sol–gel method after sintering in air at 1150°C for 2 h, the varistor possesses good electrical characteristics, with present nonlinear coefficient of ∼24.43 and breakdown voltage of ∼2487.27 V/cm.