Monodispersed electroconductive particles were prepared by nitriding c
omposite particles. The composite particles were monodispersed silica
particles coated uniformly with a titania layer. The composite was obt
ained by hydrolysis of titanium isopropoxide in the presence of silica
seed particles synthesized by hydrolysis of tetraethyl orthosilicate.
The nitriding experiments of composite particles were conducted in a
tube furnace at various temperatures and constant flow rate of ammonia
gas. Xray diffraction patterns of the composite particles after nitri
ding revealed that titanium nitride was produced at temperature higher
than 973 K. From scanning electron micrographs, it was found that com
posite particles after nitriding are maintained as monodispersed forms
of seed particles. The electroconductivity of the composite particles
after nitriding is high enough for practical usage.