Cover Image

Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf

This thesis describes the effects of Germanium (Ge) substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of T11212 layered structure. Two series of T11212 superconductors were synthesized from TI₀.₈₅ Cr₂ CaCu₂₋ₓGeₓO₇₋₈ (х=0-0.6) and TI₀.₈₅ Cr₀.₁₅ Sr₂ CaCu₂₋ₓGeₓO₇...

Full description

Saved in:
Bibliographic Details
Main Author: Ali Yusuf, Azliza
Format: Thesis
Language:English
Published: 2011
Subjects:
Q Science (General)
QD Chemistry
Online Access:https://ir.uitm.edu.my/id/eprint/17656/13/17656.pdf
https://ir.uitm.edu.my/id/eprint/17656/
Tags: Add Tag
No Tags, Be the first to tag this record!
id my.uitm.ir.17656
record_format eprints
spelling my.uitm.ir.176562022-11-24T04:15:07Z https://ir.uitm.edu.my/id/eprint/17656/ Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf Ali Yusuf, Azliza Q Science (General) QD Chemistry This thesis describes the effects of Germanium (Ge) substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of T11212 layered structure. Two series of T11212 superconductors were synthesized from TI₀.₈₅ Cr₂ CaCu₂₋ₓGeₓO₇₋₈ (х=0-0.6) and TI₀.₈₅ Cr₀.₁₅ Sr₂ CaCu₂₋ₓGeₓO₇₋₈ (y=0-0.3) nominal starting compositions using the conventional solid state method. Substitution of Ge⁴⁺ in place of Cu in TI₀.₈₅ Cr₂ CaCu₂₋ₓGeₓO₇₋₈ (х=0-0.6) series showed initial increase in zero critical temperature value, Tc zero from 98 K (x=0) to 100 K (x=0.1) and in the range of 85-86 K for x= 0.2-0.3. The slow decrease in Tc zero is unexpected as tetravalent Ge⁴⁺ substitution is expected to strongly reduce hole concentration in the samples and suppress Tc zero.While for substitution of Ge⁴⁺ in place of Sr in TI₀.₈₅ Cr₀.₁₅ Sr₂ CaCu₂₋ₓGeₓO₇₋₈ (y=0-0.3) series, electrical resistance measurements showed the zero critical temperature value, Tc zero were in the range of 90-98 K for.y=0 - 0.15 and in range of 60-78 K forj;= 0.2-0.3. Analysis of excess conductivity behavior based on Aslamazov-Larkin model for the Ge free compound, revealed a 2D fluctuation behavior. However, substitution of Ge in both of the series induced 2D to 3D transition behavior with the highest transition temperature, T2D-3D observed at x= 0.10 and y= 0.10 samples. The analyses of Fourier transformation infrared (FTIR) and X-ray diffraction (XRD) data indicate increasing CuO inter-plane coupling with Ge substitution at both Cu and Sr-sites. The increment was suggested to cause sustenance of the high Tc zero and metallic normal state behavior for x= 0-0.30 and y= 0.03-0.15 samples. This is supported by the excess conductivity analysis using the Lawrence Doniach model which also indicates an increase in the inter-plane coupling (J) values. It was suggested that the increase in inter-plane coupling may enhance correlation between the carrier of the superconducting samples which then decrease the anisotropy and resulted to better superconducting properties of the samples. 2011-09 Thesis NonPeerReviewed text en https://ir.uitm.edu.my/id/eprint/17656/13/17656.pdf Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf. (2011) Masters thesis, thesis, Universiti Teknologi MARA (UiTM). <http://terminalib.uitm.edu.my/17656.pdf>
institution Universiti Teknologi Mara
building Tun Abdul Razak Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Teknologi Mara
content_source UiTM Institutional Repository
url_provider http://ir.uitm.edu.my/
language English
topic Q Science (General)
QD Chemistry
spellingShingle Q Science (General)
QD Chemistry
Ali Yusuf, Azliza
Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
description This thesis describes the effects of Germanium (Ge) substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of T11212 layered structure. Two series of T11212 superconductors were synthesized from TI₀.₈₅ Cr₂ CaCu₂₋ₓGeₓO₇₋₈ (х=0-0.6) and TI₀.₈₅ Cr₀.₁₅ Sr₂ CaCu₂₋ₓGeₓO₇₋₈ (y=0-0.3) nominal starting compositions using the conventional solid state method. Substitution of Ge⁴⁺ in place of Cu in TI₀.₈₅ Cr₂ CaCu₂₋ₓGeₓO₇₋₈ (х=0-0.6) series showed initial increase in zero critical temperature value, Tc zero from 98 K (x=0) to 100 K (x=0.1) and in the range of 85-86 K for x= 0.2-0.3. The slow decrease in Tc zero is unexpected as tetravalent Ge⁴⁺ substitution is expected to strongly reduce hole concentration in the samples and suppress Tc zero.While for substitution of Ge⁴⁺ in place of Sr in TI₀.₈₅ Cr₀.₁₅ Sr₂ CaCu₂₋ₓGeₓO₇₋₈ (y=0-0.3) series, electrical resistance measurements showed the zero critical temperature value, Tc zero were in the range of 90-98 K for.y=0 - 0.15 and in range of 60-78 K forj;= 0.2-0.3. Analysis of excess conductivity behavior based on Aslamazov-Larkin model for the Ge free compound, revealed a 2D fluctuation behavior. However, substitution of Ge in both of the series induced 2D to 3D transition behavior with the highest transition temperature, T2D-3D observed at x= 0.10 and y= 0.10 samples. The analyses of Fourier transformation infrared (FTIR) and X-ray diffraction (XRD) data indicate increasing CuO inter-plane coupling with Ge substitution at both Cu and Sr-sites. The increment was suggested to cause sustenance of the high Tc zero and metallic normal state behavior for x= 0-0.30 and y= 0.03-0.15 samples. This is supported by the excess conductivity analysis using the Lawrence Doniach model which also indicates an increase in the inter-plane coupling (J) values. It was suggested that the increase in inter-plane coupling may enhance correlation between the carrier of the superconducting samples which then decrease the anisotropy and resulted to better superconducting properties of the samples.
format Thesis
author Ali Yusuf, Azliza
author_facet Ali Yusuf, Azliza
author_sort Ali Yusuf, Azliza
title Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
title_short Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
title_full Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
title_fullStr Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
title_full_unstemmed Effects of Germanium substitutions at Cu/Sr sites on fluctuation induced conductivity and interplanar coupling of TI₀.₈₅Cr₀.₁₅Sr₂CaCu₂O₇₋₈ superconductor / Azliza Ali Yusuf
title_sort effects of germanium substitutions at cu/sr sites on fluctuation induced conductivity and interplanar coupling of ti₀.₈₅cr₀.₁₅sr₂cacu₂o₇₋₈ superconductor / azliza ali yusuf
publishDate 2011
url https://ir.uitm.edu.my/id/eprint/17656/13/17656.pdf
https://ir.uitm.edu.my/id/eprint/17656/
_version_ 1751539765428092928
score 13.211869

Similar Items