Dielectric properties of laser-ablated HfO2 particles

Dielectric properties of hafnium dioxide (HfO2) nanoparticles obtained by pulsed laser ablation have been studied by impedance spectroscopy in a frequency range from 50 to 10(5) Hz. It is established that the dielectric permittivity of obtained particles depends on the degree of porosity of the ablated material, As the porosity decreases, both real (E >') and imaginary (E > aEuro(3)) components of the complex dielectric permittivity tend to increase. According to analysis in the framework of the Bruggeman effective medium approximation, the static dielectric permittivity of obtained HfO2 nanoparticles amounts to E > aEuro(2) = 24 +/- 2.