Measurement of the complex permittivity of metal nanoislands and the surface resistance of thin conducting films at microwave frequencies

Abstract

Split-post and single-post dielectric-resonator techniques have been used for measurements of the complex permittivity of metal nanoislands and the surface resistance of thin conducting films. These two complementary techniques permit measurements of materials having the imaginary part of the relative permittivity in several decades range from the values characteristic for low loss dielectrics to that of well conducting metals. The complex permittivity measurements have been performed on thin film aluminum patterns in the form of concentric rings cut radially into different numbers of sectors. The measurements have shown that with decreasing length of the sectors the complex permittivity of such created meta-material undergoes a transition from that of a metallic state to that characteristic of a dielectric with a giant real permittivity (>2 × 105). The evolution of both the real and the imaginary parts of the permittivity with sector length depends on the film thickness.