Abstract: PEG6000/nano-Ni(OH)₂ sol was prepared by a modified sol-gel method with Ni(Ac)₂. The stable region of
the sol was definited by measuring the viscosity of the sol. Furthermore the flow patterns of the stable sol were studied and the results show that the
stable sol has two flow patterns: Newtonian and pseudoplastic fluid. With the Newtonian fluid of the stable sol, the nano-NiO thin films were produced
by the spin-coating method. The research results indicate that the thickness of the film (d) is largely determined by the factors including angular velocity
(ω), the apparent viscosity of the sol (η) and the content of Ni(OH)₂(M) to the equation: d=K((η^0.74M^2.1)/(ω^0.54)). The quality of the films is influenced
by the flow patterns and the content of PEG of the stable sol. The surfaces of the thin films with Newtonian sol are smooth while those
with pseudoplastic sol are rough and wavy. The surfaces of nano-NiO films with high content of Ni(OH)₂ and low content of PEG6000 are compact and
dense while those with low content of Ni(OH)₂ and high content of PEG6000 are loose.

Key words: nano-NiO, thin film, sol-gel spin-coating method, rheology