The scaling of the AC conductivity in quantum critical holographic theories at finite density, temperature, and presence momentum dissipation is considered. It shown that there generically an intermediate window frequencies which IR clearly visible.1 MoreReceived 14 August 2020Revised 13 November 2020Accepted 16 2020DOI:https://doi.org/10.1103/PhysRevResearch.3.013028Published by American Physi...

Polycrystalline samples of Gd-modified Lead Zirconate Titanate [PGZT; Pb1-xGdx(Zr0.65Ti0.35)1-x/4O3] ceramics (where, x = 0.00, 0.06 and 0.09) were prepared using high temperature mixed oxide method at sintering temperature 1450 K. Preliminary structural analysis through X-ray diffraction technique suggests their formation in single phase tetragonal crystal system at room temperature. From the ...

The dc and ac conductivities of carbon nanotubes-polyepoxy composites have been investigated from 20 to 110 °C in the frequency range 10-10 Hz as a function of the conductive weight fraction p ranging from 0.04 to 2.5 wt %. The frequency dependence of the measured conductivity obeys the universal dynamic response (UDR): a dc plateau followed, above a critical frequency ωc, by the ω power law wi...

The oxygen reduction reaction (ORR) is one of the major factors that is limiting the overall performance output of microbial fuel cells (MFC). In this study, Platinum Group Metal-free (PGM-free) ORR catalysts based on Fe, Co, Ni, Mn and the same precursor (Aminoantipyrine, AAPyr) were synthesized using identical sacrificial support method (SSM). The catalysts were investigated for their electro...

We study in this paper the scaling and statistical properties of the ac conductivity of thin metal-dielectric films in different regions of the loss in metallic components and particularly in the limit of vanishing loss. We model the system by a 2D RL − C network and calculate the effective conductivity by using a real space renormalization group method. It is found that the real conductivity s...

The electrical properties of cement-based composites with mono-size conductive (steel) or insulating (glass) spherical inclusions were investigated by combined 2-point impedance spectroscopy and 4-point dc resistance measurements. The matrix was ordinary Portland cement (w/c = 0.4; cured for 7 days). Particle loading was varied over an extended range to as high as 42% volume fraction. The steel...