22 research outputs found
The feasibility of correlation between superconductivity and magnetic monopole: Establishment of semi-classical electrodynamics projection, TKH topological theory and dynamic vortex models
In this paper, a feasibility of semi-classical electromagnetic description
together with experimental data, T-K-H topological and dynamic models and
theory of vortex considered to justify the relation between superconductivity
phenomena and magnetic monopole. We find that the electromagnetic energy of
magnetic monopole is in agreement with vortex energy in topological theory and
it can get close to thermal energy at room temperature. Indeed, these models
suggest that the origin of the hot superconductivity may be magnetic monopoles
with QM-Cl = 137 e (magnetic charge in classical approach) or QM-Q =137/2 e
(magnetic charge in quantum approach), and the electrical conductivity is
related to the mobile monopole or vortices. This research shows that the
electrical permittivity ({\epsilon}) and magnetic permeability ({\mu}) of
matter have a key role in the superconductive properties. We propose that this
model may justify the hot superconductivity properties.Comment: 24 pages, 5 figure
Influence of Deposition Temperature as a Reducing Agent on Synthesis of Reduced Graphene Oxide (RGO) Nanosheets
In this paper we have investigated the physical properties of reduced graphene oxide (RGO) thin films prepared at various substrate temperatures of 230, 260, 290, 320 and 350 oC using spray pyrolysis technique. We have compared these films from various viewpoints, including structural, morphological, optical, electrical and thermos-electrical properties. XRD analysis showed a phase shift from graphene oxide (GO) to RGO due to elevate the substrate temperature from 200 oC to higher temperatures. FESEM images of RGO thin films reveal that a stacked image of irregular and folding nanosheets, and rod-like features at temperatures below and above 290 oC; respectively. Optical studies showed that the layers have a relatively high absorption coefficient (∼0.8×104 to 1.7×104 cm−1) in the visible range, with an optical band gap of 1.67–1.88 eV. The Hall effect data showed that all samples have a p-type conductivity with a hole concentration of ∼1015 cm−3, and sheet resistance values of about 106 Ω/sq, in agreement with previous reports. The thermoelectric measurements revealed that with increasing applied temperature gradient between the two ends of the samples, the thermoelectric electromotive force (emf) of the prepared RGO thin films increases
Magneto-optic properties and optical parameter of thin MnCo films
Having precise hysterics loop of thin ferroelectric and ferromagnetic layers for optical switching and optical storages are important. A hysterieses loop can be achieved from a phenomenon call the magneto-optic effect. The magneto-optic effect is the rotation of a linear polarized electromagnetic wave propagated through a ferromagnetic medium. When light is transmitted through a layer of magnetic material the result is called the Faraday effects and in the reflection mode Kerr effect. In the present work we prepared a thin layer of MnxCo3-xO4 (0≤ x ≤ 1) and a binary form of MnO/Co3O4 by the spray pyrolysis method. The films have been characterized by a special set up of magneto-optic hysterics loop plotter containing a polarized He- Ne laser beam and a special electronic circuit. Faraday rotation were measured for these films by hysterics loop plotter and their optical properties were also obtained by spatial software designed for this purpose according to Swane Poel theoretical method. The measurements show that the samples at diluted Mn study has are ferromagnetic and the magneto-optic rotation show a good enhance respect to the single Co layers. Also, the study has shown that the MnCo oxide layer have two different energy gaps and by increasing of Mn this energy decreases and fall to 0.13 eV