89,203 research outputs found
Structural, Electrical Properties and Dielectric Relaxation in Na+ Ion Conducting Solid Polymer Electrolyte
Present paper reports, the structural, microstructural, electrical,
dielectric properties and ion dynamics of a sodium based solid polymer
electrolyte films comprising of PEO8-NaPF6+ x wt. % SN. The structural and
surface morphology properties have been investigated by XRD and FESEM.
Different microscopic interaction among the polymer, salt and SN have been
analyzed through FTIR. The dielectric permittivity and loss tangent enable us
to estimate the dc conductivity, dielectric strength, double layer capacitance,
and relaxation time. The loss tangent relaxation peak shifts towards
high-frequency side which indicates the decrease of relaxation time and faster
ion dynamics. Further, the relation among various relaxation times ...... has
been developed systematically. The ionic conductivity has been estimated in
whole frequency window including JPL and displays strong dependency on SN
content. The sigma representation ........ has been introduced for exploring
the ion dynamics by highlighting the dispersion region in Cole-Cole plot
(........) at lower frequency window and increase in the radius of semicircle
indicates a decrease of relaxation time. A well convincing/logical scheme has
been proposed which justify the recorded experimental data
Optimization of salt concentration and Explanation of Two Peak Percolation in Blend Solid Polymer Nanocomposite Films
The present paper report is focused toward the preparation of the flexible
and freestanding blend solid polymer electrolyte films based on PEO-PVP
complexed with NaPF6 by solution cast technique. The structural/morphological
features of the synthesized polymer nanocomposite films have been investigated
in detail using X-ray diffraction, Fourier transform infra-red spectroscopy,
field emission scanning electron microscope, and atomic force microscopy
techniques. The film PEO-PVP+NaPF6 O/Na:8 exhibits highest ionic conductivity
~5.92x10-6 S cm-1 at 40 oC and ~2.46x10-4 S cm-1 at 100 oC. The temperature
dependent conductivity shows Arrhenius type behavior and activation energy
decreases with the addition of salt. The high temperature (100 oC) conductivity
monitoring is done for the optimized PEO-PVP+NaPF6 O/Na:8 highly conductive
system and the conductivity is still maintained stable up to 160 h (approx. 7
days). The thermal transitions parameters were measured by the differential
scanning calorimetry (DSC) measurements. The prepared polymer electrolyte film
displays the smoother surface in addition of salt and a thermal stability up to
300 oC...........
The BCS theory of q-deformed nucleon pairs - qBCS
We construct a coherent state of q-deformed zero coupled nucleon pairs
distributed in several single-particle orbits. Using a variational approach,
the set of equations of qBCS theory, to be solved self consistently for
occupation probabilities, gap parameter Delta, and the chemical potential
lambda, is obtained. Results for valence nucleons in nuclear degenerate sdg
major shell show that the strongly coupled zero angular momentum nucleon pairs
can be substituted by weakly coupled q-deformed zero angular momentum nucleon
pairs. A study of Sn isotopes reveals a well defined universe of (G, q) values,
for which qBCS converges. While the qBCS and BCS show similar results for Gap
parameter Delta in Sn isotopes, the ground state energies are lower in qBCS.
The pairing correlations in N nucleon system, increase with increasing q (for q
real).Comment: 8 pages, REVTEX, 3 eps figure
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