  The dielectric properties of NiO thin films grown by pulsed laser deposition
have been studied as a function of strain at temperature from 10 to 300 K.
Above 150 K, the contribution of space-charge polarization to the dielectric
permittivity of NiO films becomes dominant and the more defective films, which
were grown at low temperatures show a drastical increase in the dielectric
constant up to room temperature. While the atomically-ordered film, which was
grown at high temperature doesn't show any considerable change in the
dielectric constant in the range from 10 to 300 K. Below 100 K, the effect of
strain on the dielectric constant becomes clear. An increase in dielectric
permittivity is observed in the strained films while the relaxed film doesn't
show any remarkable deviation from its bulk value. The low-temperature
dielectric behavior of NiO thin film can be interpreted based on the effect of
strain on the lattice dynamics of rocksalt binary oxides.
