Proprietà di trasporto dei vetri ionici: rilevanza del moto di hopping

The paper investigates the dielectric properties of the (Ag_2SO_4)_x(AgPO_3)_1_-_x and (Ag_2SO)_x(AgPO_3)_1_-_x glasses by impedance measurements at low frequencies (l Hz to l0 MHz)and at high frequencies (8.2 GHz to l8 GHz) by waveguide measurements. The frequency dependence of a.c. conductivity has been interpreted in terms of translational and reorientational ionic hopping motion. The activation energies values extracted from the temperature dependence of fixed frequency a.c. conductivity agree with the values of the acoustic attenuation

Frequency and gate voltage effects on the dielectric properties and electrical conductivity of Al∕SiO2∕p-Si metal-insulator-semiconductor Schottky diodes

The dielectric properties and electrical conductivity of Al∕SiO2∕p-Si (MIS) Schottky diodes (SDs) in the frequency range of 10 kHz to 10 MHz and the gate voltage range of −2 to 6 V have been investigated in detail using experimental C-V and G∕w-V measurements. Experimental results indicated that the voltage dependence of the real part of the dielectric constant (ɛ′) and loss tangent (tan δ) characteristics have a peak at each frequency. The values of ɛ′ increase with decreasing frequency and tend to be frequency independent in the negative voltage region. However, the values of the dielectric loss (ɛ″) increase with decreasing frequency at each voltage. In contrast, ɛ′ and ɛ″ are almost found to decrease, and the ac electrical conductivity (σac) and the real part of the electric modulus (M′) increase, with increasing frequency. In addition, the imaginary part of the electric modulus (M″) showed a peak that shifts to a higher frequency with increasing applied voltage. It can be concluded that interfacial polarization can more easily occur at low frequencies, and consequently the majority of interface states at the Si–SiO2 interface contribute to the deviation of the dielectric properties of Al∕SiO2∕p-Si (MIS) SDs