Condensed Matter

1408 Submissions

[5] viXra:1408.0216 [pdf] submitted on 2014-08-30 14:34:24

Why Feynman Does not Discuss the Electrical Resistivity of Metals?

Authors: P. R. Silva
Comments: short note, 01page, 04 references

I was surprised by the fact that, Drude’s formula for the electrical conductivity of metals, does not appear in the famous textbook: “The Feynman Lectures on Physics”.
Category: Condensed Matter

[4] viXra:1408.0186 [pdf] submitted on 2014-08-27 10:48:21

Mystery of Missing Co-ions Solved

Authors: Rajib Chakraborty
Comments: 9 Pages.

Presence of a charged wall distributes like charges (co-ions) and unlike charges (counter-ions) differently within an electrolytic solution. It is reasonable to expect that counter-ions have more population near the wall, while co-ions are abundant away from it; experiments and simulations support this. An analytical formula for the net charge-density distribution has been used widely since almost hundred years, was obtained by solving the Poisson-Boltzmann equation. However, the old formula shows excess counter-ions everywhere, cannot account for the missing co-ions satisfactorily, and clearly violates charge conservation principle. Here, I correct the distribution formula from fundamental considerations. The old derivation expresses charge-density distribution as a function of electrostatic potential through Boltzmann distribution, but missed a crucial point that the indefinite nature of electrostatic potential makes charge-density indefinite as well. We must tune electrostatic potential by adding suitable constant until the integral of charge-density becomes consistent with the net charge present in solution; old theory did not do it, that I do here. This result demonstrates how to reconcile a definite quantity to an indefinite one, when they are related. I anticipate, this result is going to have far reaching impacts on many fields like colloid science, electro-kinetics, bio-technology etc. that use the old theory
Category: Condensed Matter

[3] viXra:1408.0148 [pdf] submitted on 2014-08-23 03:02:40

On a Simple Superconductivity Model and New Superconducting Material

Authors: Zhi Cheng
Comments: 11 Pages.

In this paper, we establish a simple superconductivity model based on virtual photons exchange mechnisim. It shows that this simple model can be used to explain the supercondutivity mechanism for some superconductive materials by comparing the theoretical prediction with the experimental data. On this basis, we propose new possible structures that can produce high temperature superconductors.
Category: Condensed Matter

[2] viXra:1408.0131 [pdf] replaced on 2014-11-23 20:56:58

New Hamiltonian and Cooper Pair's Origin of Pseudogap and Colossal Magnetoresistance in Manganites

Authors: Fu-sui Liu
Comments: 37 Pages.

Based on the thirteen similarities of structures of lattice, electron, and strong correlation Hamiltonian between CMR (colossal magnetoresistance) manganites and the high-Tc cuprates, this paper concludes that the Hamiltonian of the high-Tc cuprates and CMR manganites are the same. Based on uniform and quantitative explanations for fifteen experimental facts, this paper concludes that the pseudogap and CMR of manganites are caused completely by formation of Cooper pairs, consisting of two oxygen 2pσ holes in MnO2 plane
Category: Condensed Matter

[1] viXra:1408.0093 [pdf] submitted on 2014-08-15 13:09:48

Physical Solution of Poisson-Boltzmann Equation

Authors: Rajib Chakraborty
Comments: 5 Pages.

We correct the solution of Poisson-Boltzmann equation regarding charge distribution in an electrolytic solution bounded by walls. Considering charge conservation principle properly, we show that the gradient of electrostatic potential at different walls are strictly related, and cannot be assigned independent values, unlike old theory. It clarifies some cause and effect ideas: distribution turns out to be independent of the initial polarity of walls; the accumulated charges in liquid usually induce opposite polarity on the wall surface, forms `Electric Double Layer' (EDL), contrary to the common belief that a charged wall attracts counter-ions to form EDL. Distribution depends only on the potential difference between walls and the net charge present in the solution, apart from Debye length.
Category: Condensed Matter