Sub‐THz complex dielectric constants of smectite clay thin samples with Na⁺/Ca⁺⁺ ions

Abstract

We implement a technique to characterize the electromagnetic properties at frequencies 100 to 165 GHz (3 cm−1 to 4.95 cm−1) of oriented smectite samples using an open cavity resonator connected to a submillimeter wave VNA (Vector Network Analyzer). We measured dielectric constants perpendicular to the bedding plane on oriented Na+ ion and Ca++ ion stabilized smectite samples deposited on a glass slide at ambient laboratory conditions (room temperature and room light). The clay layer is much thinner (∼30 μm) than the glass substrate (∼2.18 mm). The real part of dielectric constant, ϵre, is essentially constant over this frequency range but is larger in Na+ ion than in Ca++ ion infused clay. The total electrical conductivity (associated with the imaginary part of dielectric constant, ϵim) of both samples increases monotonically at lower frequencies (<110 GHz) but shows rapid increase for Na+ ions in the regime > 110 GHz. The dispersion of the samples display a dependence on the ionic strength in the clay interlayers, i.e., ζ potential in the Stern layers.

Dependences of the Optical and the Electrical Properties of 50 nm Thick Copper Films Deposited by Using an Electron Beam Evaporator on the Evaporator's Vacuum Conditions

“…실제로 Table 1을 참고하면, 시료 1의 경우 10 −7 torr 의 좋은 진공도를 만들기 위해서 전날 밤부터 약 15시간 정도의 펌핑 시간을 가졌고, 기판에 가장 많은 불순물이 Fig. 7(a THz, and theoretical terahertz transmittance (red dotted line) through a copper thin film with the thickness of 50 nm and the refractive index from one reference [14] on the glass slide with the refractive index of 2.0 [15]…”