This letter presents a comprehensive impedance spectroscopy characterisation of Magnéli phases (TinO2n-1) over a range of temperatures, which are of interest in electrochemistry and sensing applications, with the aim to enhance the understanding of their electrical properties and influence their microstructure. The impedance of the TinO2n-1 can be resolved into two different contributions, name...

We theoretically study the feasibility of amplification and generation of terahertz radiation in dc-ac-driven semiconductor superlattices in the absence of electric domains. We find that if in addition to a dc bias a strong terahertz pump field is applied, a Bloch gain profile for a small terahertz signal can be achieved under the conditions of a positive static differential conductivity. Here,...

We calculate the effect of the electron-phonon interaction on the electronic density of states DOS , the quasiparticle properties, and on the optical conductivity of graphene. In metals with DOS constant on the scale of phonon energies, the electron-phonon renormalizations drop out of the dressed DOS, however, due to the Dirac nature of the electron dynamics in graphene, the band DOS is linear ...

The effect of Zn substitution on the DC electrical resistivity, AC electrical conductivity and microstructure of V2O5 doped Zn(1-x)NixFe2O4 with x=0.0, 0.1, 0.2, 0.3, 0.4 (5 samples) were prepared by conventional ceramic technique has been investigated. The structural characterization of nickel-zinc ferrites were done by X-ray diffraction technique. Micro-structural and morphological studies we...

We have analyzed the constant loss contribution to the ac conductivity in the frequency range 10 Hz-1 MHz and temperatures down to 8 K, for two Li ionic conductors, one crystalline (Li(0.18)La(0.61)TiO(3)) and the other glassy (61SiO(2);35Li(2)O.3Al(2)O3.P(2)O(5)). As temperature is increased a crossover is observed from a nearly constant loss to a fractional power law frequency dependence of t...

The structure and dynamics of the solutions of LiPF6 in propylene carbonate over a concentration range of 0-3 mol/kg are studied with neutron spin echo spectroscopy, alternating-current (AC) conductometry, and shear impedance spectroscopy. The neutron diffraction shows a prepeak at ≈10 nm(-1) in addition to the main peak at ≈14 nm(-1) when the concentration of the salt is no less than 2 mol/kg....

The dielectric dispersion behaviour of montmorillonite (MMT) clay nanoparticles colloidal suspension in poly(vinyl pyrrolidone)-ethylene glycol (PVP-EG) blends were investigated over the frequency range 20 Hz to 1 MHz at 30°C. The 0, 1, 2, 3, 5 and 10 wt% MMT clay concentration of the weight of total solute (MMT+PVP) were prepared in PVP-EG blends using EG as solvent. The complex relative diele...

Fast ion conducting (FIC) glasses of composition 66%AgI-[MAg2O-F{(F1)B2O3-(F2)TeO2}] were prepared by melt quenching technique. Here M/F ratio was varied from 0.0 to 2.0 in steps of 0.25 for fixed values of F1& F2. The prepared samples were characterized by X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR) experiments to understand their structure. Electrical studies of the prepared...

Electrical relaxation data of crystalline yttria-stabilized zirconia are used to analyze the permittivity change observed in the spectra of the real part of the permittivity in ionic conducting materials. It is found that this permittivity change is independent of both temperature and mobile-ion concentration, and it is determined solely by the degree of interaction among ions in the relaxation...

THz frequency-domain transmittance measurements were carried out on chemical-vapor-deposited (CVD) graphene films transferred to high-resistivity silicon substrates, and packaged as back-gated graphene field effect transistors (G-FETs). The graphene AC conductivity σ(ω), both real and imaginary parts, is determined between 0.2 and 1.2 THz from the transmittance using the transmission matrix met...