Specific Features of the Conductivity of Chromium Films with a Thickness of Several Nanometers

Specific features of the interaction of terahertz radiation with nanometer-thick chromium films deposited on quartz substrates are analyzed. Optical coefficients of chromium films with thicknesses ranging from 1.5 to 40 nm are measured in a frequency range of 0.25–1.1 THz. Pulsed spectroscopic measurements employ a picosecond oscillator. A maximum absorption coefficient of 43% is measured at a film thickness of 10 nm. Theoretical calculations of optical coefficients are performed with the aid of expressions that take into account a phenomenological dependence of conductivity on film thickness. It is demonstrated that the conductivity of thick chromium films (20–40 nm) is less than the conductivity of bulk metal by an order of magnitude.