Abstract: We realized morphology control of ZnO crystals and prepared ZnO particles with variety of
shapes such as hexagonal, ellipse, two large needles with small needles and multi-needles. The
morphology control was achieved by the control of super saturation degree of aqueous solutions. All
of the particles showed X-ray diffraction of single ZnO phase. The control of crystal growth and
particle morphology in this system would contribute to the development of future crystalline
materials and devices.
Abstract: To fabricate porous and thick alumina films, we prepared an aqueous alumina hydroxide sol
containing trehalose. The alumina films were deposited by dip-coating technique on glass substrates
and heating at 500 °C. The maximum thickness of the film obtained by one-run dip-coating using the
sol containing trehalose was over 1000 nm. The film was an aggregate of alumina particles with a
diameter of 20-40 nm and pores were interstices between the particles. The porosity of alumina film
can be controlled in the range of 48-65 % by changing trehalose concentration in the dip-coating
Abstract: Barium titanate nanoparticle (BT-NP) suspensions were prepared by dispersing sol-gel-derived
BT-NPs in ethylene glycol monomethyl ether (EGMME) under sonication. When an electric field
was applied, a part of the BT-NPs in a suspension was deposited on the cathode by
electrophoretically deposition and most of the rest of the BT-NPs settled down towards the bottom
of a container. The concentration of BT-NPs in the lower part of the container (Cbottom) increased
with time until the Cbottom reached a specific concentration (threshold concentration) at which
sedimentation of BT-NPs start to occur. The threshold concentration of the nanoparticles
sedimentation gave a significant influence upon the aspect of a BT-NPs deposit formed on the
Abstract: We have demonstrated a fabrication procedure for spin-electronic devices by using two-dimentional
titania nanosheets. Magneto-optical Kerr measurements demonstrate that Co-substituted titania
nanosheets (Ti0.8Co0.2O2) act as nanoscale ferromagnetic layers at room temperature, and their
multilayer-assemblies exhibit robust magnetic circular dichroism (104–105 deg/cm) near the
absorption edge at 260 nm, an operating wavelength being the shortest attained so far. The
availability of ferromagnetic nanostructures and their molecule-level assembly allow the rational
design and construction of high-efficiency magneto-optical devices by forming superlattices.
Abstract: Vertically aligned carbon nanotubes (CNTs) were grown on a stainless steel substrate (SUS304)
by resistance-heating method in alcohols containing homogeneously dissolved cobaltocene
Co(C5H5)2 as a catalyst source. Straight-chain primary alcohols, 1,2-ethanediol and cyclohexanol
were used as carbon sources to examine the effects of the molecular structures on the morphology
of the aligned CNTs. Methanol brought the best purity and alignment of CNTs of all the alcohols.
The CNTs from 1,2-ethanediol was worse in the purity than those from ethanol with the same
number of carbon atoms. The CNTs from cyclohexanol had a better purity than those from
1-hexanol. Distinctive features of this method are simple, low cost and a one-step process involving
none of vacuum processes and catalyst preparation processes.
Abstract: Aligned carbon nanotube arrays (CNTAs) were readily synthesized by a resistance heating method
on a substrate of commercially available stainless steel which has more plentiful availability than
the wafers of Si and quarts. The catalyst was supported on the substrate by dip coating with a
methanol solution of M(C5H5)2(M=Co,Fe), and the substrate was electrically heated at 800oC in
methanol. Highly aligned CNTAs were grown from the catalyst prepared from 0.02 M Co(C5H5)2
methanol solution. The alignment was influenced by the concentration and the kind of M(C5H5)2.
Abstract: The series of partially Al-substituted lithium manganese oxides were prepared by spray pyrolysis
process from spray solutions with citric acid and ethylene glycol. The as-prepared particles obtained
from spray solution with citric acid and ethylene glycol turned to fine-sized LiMn(12-
x)/6Alx/6O4(0.05≤x≤2) particles with regular morphology after post-annealing. The discharge
capacities of the particles post-annealed at temperature of 800oC changed from 128 to 84 mAh/g
when the x of the LiMn(12-x)/6Alx/6O4 particles was changed from 0 to 2. The Al-doped LiMn2O4 fine
particles prepared by spray pyrolysis from spray solution with citric acid and ethylene glycol had
good cycle properties.
Abstract: We synthesized barium titanate (BaTiO3) nanoparticles by sol-gel process and investigated their
crystallization behavior using differential scanning calorimetry and X-ray diffraction. BaTiO3
nanoparticles with various degrees of crystallinity were obtained by adjusting synthesis conditions.
Under aging conditions that do not allow dealcholization reaction to complete, many hydroxyl
ligands remain in as-synthesized BaTiO3 nanoparticles, resulting in the formation of voids or
defects in the nanoparticles after calcination. It is essential to use high concentration alkoxides
precursor solutions for producing BaTiO3 nanoparticles with high crystallinity at low temperature.
Abstract: BaTiO3 nano-sized powders were successfully prepared by spray pyrolysis using multiphase
plasma under the air atmosphere. The particles characteristics of BaTiO3 nano-sized powders were
studied by SEM and XRD. The effect of volume of arc plasma and precursor solution on the
formation of BaTiO3 nano-sized powders was investigated. The use of Ba-Ti complex precursor
solution derived from lactic acid led to formation of tetragonal BaTiO3 nano-sized powders with
140 nm size. As for BaTiO3 ceramics, the effect of sintering temperature on relative density and the
temperature dependence of dielectric properties were investigated.