The electrical conductivity, U, and thermoelectric power, S , of the solid solutions (Dy,Y,-x)2M0207 have been measured in the temperature range 300-10 K. Log(aT) versus 1/T and S versus 1/T plots were found to be linear down to about 100 K. The activation energies E, and Es obtained from conductivity and thermoelectric power measurements, respectively, differ by one order of magnitude, indsati...

The time-dependent role of cations was investigated by ageing four different aqueous solutions of cation chlorides. A linear correlation was found between the cations’ Setchenov coefficient for the salting-out of benzene and the increase in the conductivity with time. The conductivity of the structure-breaking cations or the chaotropes increased more significantly with time than the conductivit...

The transmission electron microscopy images of in situ prepared multiwall carbon nanotubes MWNTs and polyaniline PANI composites show that nanotubes are well dispersed in aqueous medium, and the nanofibers of PANI facilitate intertube transport. Although low temperature transport indicates variable range hopping VRH mechanism, the dc and ac conductivity become temperature independent as the MWN...

The Kubo formula for the electrical conductivity of per stratum of few-layer graphene, up to five, is analytically calculated in both simple and Bernal structures within the tight-binding Hamiltonian model and Green's function technique, compared with the single-layer one. The results show that, by increasing the layers of the graphene as well as the interlayer hopping of the nonhybridized p z ...

Upon electrochemical oxidation the hedgehogtype core-shell system 1 forms a network which can be charged and discharged in the potential range between 0.4 and 1.5 V. In-situ conductivity measurements (Figure 1) of the coupling product of 1 show an increase of the conductivity during voltammetric charging of the thiophene chains in the deposited material. This conductivity passes a maximum appro...

Bulk BaxSr1 xCoyFe1 yO3 d compositions (BSCF) were synthesized by the solid-state reaction method. The electrical conductivity of ceramic bars was measured using a dc four-probe method as a function of temperature in air up to 970 °C. All compositions showed thermally activated p-type semi-conductivity up to ~450 °C and then a transition to metal-like conductivity. The smallpolaron hopping p-ty...

Qualitatively new transport mechanism is suggested for hopping of carriers according to which the variable-range hopping (VRH) arises from the resonant tunneling between transport states brought into resonance by Coulomb potentials produced by surrounding sites with fluctuating occupations. A semiquantitative description of the hopping transport is given based on the assumption that fluctuation...

The phenomenon of electrical conductivity maxima of molten salts versus temperature during orthobaric (closed-vessel) conditions is further examined via ab initio simulations. Previously, in a study of molten BiCl3, a new theory was offered in which the conductivity falloff at high temperatures is due not to traditional ion association, but to a rise in the activation energy for atomic ions hop...

in this research work nano porous silicon layers with different porosity were prepared by using electrochemical etching. surface morphology and size of pores were investigated by scanning electron microscopy (sem).tio2 thin films with ebpvd method have been deposited on the surface of psi layers. the influence of anodization conditions such as anodization time interval and current density on el...

Abstract A variable range hopping (VRH) transport mechanism can be induced in molecular beam epitaxial, n-type doped InSb wafers with focussed Ga + ion damage. This technique allows areas of wafer to selectively damaged and then subsequently processed into gated metal–insulator–semiconductor (MIS) devices where a disordered, two-dimensional (2D) device established. At high levels damage (dose &...