Fluctuation-enhanced conductivity in YBa2Cu3Ox (6.5≤x≤6.95) and Tl2Ba2Ca2Cu3O10±δ superconducting thin films

Juang, Jenh‐Yih; Hsieh, M. C.; Luo, Chih-Wei; Uen, T. M.; Wu, Kaung‐Hsiung; Gou, Y. S.

doi:10.1016/s0921-4534(99)00566-3

Cited by 21 publications

(18 citation statements)

References 15 publications

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“…In general, three different phases of YBCO exist: Y-123 with 90 K, Y-124 with 84 K and Y-247 with 65 K, respectively [2][3][4][5]. The YBCO system is capable of high current carrying capacity at liquid nitrogen temperature and has simple fabrication compared to the other HT c superconductors such as Bi-or Tl-based system [6,7].…”

Section: Introductionmentioning

confidence: 99%

Investigation of thermoelectric power with modification of two band model with linear T term for superconductors and thermal conductivity study of Se added YBCO samples

Altın

Aksan

Yakıncı

2014

Journal of Alloys and Compounds

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Section: Introductionmentioning

confidence: 99%

Investigation of thermoelectric power with modification of two band model with linear T term for superconductors and thermal conductivity study of Se added YBCO samples

Altın

Aksan

Yakıncı

2014

Journal of Alloys and Compounds

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“…The SFB in high temperature superconductors was suggested to imply formation of Cooper pairs well above T c , which induce excess conductivity in the normal state region. Analysis of the excess conductivity such as using the AL and LD models can give important parameters such as coherence length along c-axis, ξ c (0) [25][26][27], transition temperature, T 2D-3D [27][28][29], and interplanar coupling constant, J [30][31][32]. In (Cu,Tl)-based superconductors, i.e., (Cu,Tl)-1223 [33][34][35], (Cu,Tl)-1212 [36], and (Cu,Tl)-1245 [37] excess conductivity analysis revealed crossover from 2D to 3D transition behavior as temperature was lowered.…”

Section: Introductionmentioning

confidence: 99%

“…The analysis of excess conductivity was carried out by using the AL and LD models as a framework to determine the effect of Ce on dimensionality of SFB [59], ξ c (0) [25][26][27], γ [33], and J [30][31][32]. FTIR absorption spectra were analyzed to investigate the changes in phonon modes as a result of the substitution.…”

Section: Introductionmentioning

confidence: 99%

Influence of Ce Substitution at Sr-Site on Superconducting Fluctuation Behavior and Infrared Absorption of Tl0.9Bi0.1Sr2−x Ce x Ca0.9Y0.1Cu1.99Fe0.01O7−δ (x=0–0.20) Ceramics

Ismail

Yahya

Khan

2012

J Supercond Nov Magn

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Ce substituted Tl 0.9 Bi 0.1 Sr 2−x Ce x Ca 0.9 Y 0.1 Cu 1.99 Fe 0.01 O 7−δ (x = 0-0.20) samples were synthesized to determine the effects of the higher valence ion substitution on superconductivity and structure of the Fe-doped Tl1212 derivatives. The normal state behavior for x = 0 showed semiconductor-like behavior which gradually turned to metallic behavior with increasing Ce at x = 0.05-0.15. However, further substitution of Ce for x > 0.15 turned the normal state to insulating behavior. The zero critical temperature, T c zero increased from 65.4 K (x = 0.05) to 71.0 K (x = 0.10), but slightly decreased for x > 0.10 indicating the optimum value of average copper valence was achieved at x = 0.10. Excess conductivity analysis using the Aslamazov Larkin, AL and Lawrence-Doniach, LD models revealed two-dimensional, 2D to three-dimensional, 3D transition of superconducting fluctuation behavior, SFB with the highest transition temperature, T 2D-3D at x = 0.10. FTIR analysis in conjunction with XRD results showed softening of FeO 2 /CuO 2 planar oxygen mode from 610.5 cm −1 (x = 0) to 605 cm −1 (x = 0.20) which is suggested to be related to possible increase of inter plane coupling, J and this is supported by computed results based on the LD model. The enhanced J increases superconducting coherence length along c-axis, ξ c (0), and hence lowers anisotropy, γ resulting in enhanced superconducting properties.

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“…and A is the temperature independent amplitude that is given by [13][14][15][16] A 3D = e 2 /32 ξ c (0) (4)…”

Section: For (2d) Fluctuationsmentioning

confidence: 99%

Fluctuation Induced Conductivity in Hg-Doped (Cu0.5Tl0.5−x Hg x )Ba2Ca3 Cu 4O12−δ Superconductor

Mumtaz

Hasnain

Khan

2011

J Supercond Nov Magn

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The fluctuation induced conductivity (FIC) analysis on resistivity data of the Hg-doped (Cu 0.5 Tl 0.5−x Hg x ) Ba 2 Ca 3 Cu 4 O 12−δ (x = 0, 0.15, 0.25, 0.35) superconductor has been carried out in the light of the AslamazovLarken (AL) theory. The superconducting properties have been improved with Hg-doping (up to x = 0.25) at Tl sites in the Cu 0.5 Tl 0.5 Ba 2 O 4−y charge reservoir layer. These samples are also post-annealed in oxygen to improve intergrain connectivity and to optimize the carriers' density in CuO 2 planes. The results of FIC analysis have shown three-dimensional (3D) and two-dimensional (2D) fluctuations in the order parameters. It has been observed that there is an increase in the cross-over temperature (T o ) as well as in zero resistivity critical temperature {T c (0)} with Hgdoping. These properties have been further improved after post-annealing in oxygen, which may be due to improved inter-grain coupling and optimization of mobile carriers in CuO 2 planes. A direct correlation between T o , T c (0) as well as zero temperature coherence length ξ c (0) has been observed.

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Fluctuation-enhanced conductivity in YBa2Cu3Ox (6.5≤x≤6.95) and Tl2Ba2Ca2Cu3O10±δ superconducting thin films

Cited by 21 publications

References 15 publications

Investigation of thermoelectric power with modification of two band model with linear T term for superconductors and thermal conductivity study of Se added YBCO samples

Investigation of thermoelectric power with modification of two band model with linear T term for superconductors and thermal conductivity study of Se added YBCO samples

Influence of Ce Substitution at Sr-Site on Superconducting Fluctuation Behavior and Infrared Absorption of Tl0.9Bi0.1Sr2−x Ce x Ca0.9Y0.1Cu1.99Fe0.01O7−δ (x=0–0.20) Ceramics

Fluctuation Induced Conductivity in Hg-Doped (Cu0.5Tl0.5−x Hg x )Ba2Ca3 Cu 4O12−δ Superconductor

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