Fluctuation-induced conductivity of five planar Cu0.5Tl0.5Ba2Ca4−xMgxCu5O14−δ (x=1,2) superconductors

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

“…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. Y123 [38,39] system have also shown 2D to 3D fluctuation behavior.…”

Distinct effects of Al3+ substitution at Cu-site and Al2O3 addition on step-like elastic anomalies and electron–phonon coupling constant in EuBa2Cu3O7−δ superconductors

“…Although numerous studies on high-temperature superconductors using different techniques to understand their superconducting and normal state behaviors have been reported since their discovery, the mechanism of hightemperature superconductivity is still not definite. While most attention has been focused in the region below the onset of superconductivity, T c onset several intriguing phenomena such as existence of pseudogap [1][2][3][4], excess conductivity [5], superconducting fluctuation behavior [6,7] and elastic anomalies [8][9][10] were observed at higher temperatures. Although these phenomena do not fall in the superconducting region, they were reported in superconducting samples and therefore must be properly studied to verify if they act as vital precursors to high-temperature superconductivity taking place at much lower temperatures.…”

Enhanced three-dimensional excess conductivity in Be-doped Cu0.5Tl0.5Ba2Ca3−xBex Cu4O12−δ (x=,0.5,0.75,1.0,1.25,1.5) superconductors

“…14 We have earlier synthesized Cu 0.5 Tl 0.5 Ba 2 Ca 4−x Mg x Cu 5 O 14−␦ ͑x =1,2͒ and Ni-doped Cu 0.5 Tl 0.5 Ba 2 Ca 2 Cu 3−y Ni y O 10−␦ ͑y = 0 , 0.5, 1.0, 1.5͒ superconductors at normal pressure and studied their and fluctuation induced conductivity. 15,16 In the former, the excess conductivity data of sample fitted well with 2D, 3D AslamasovLarkin ͑AL͒ equations in oxygen annealed samples, which have also shown improved weak link behavior. 15 The Fluctuation induced conductivity ͑FIC͒ investigation of the latter revealed that Ni doping resulted in shifting of the crossover temperature to lower values through the scattering of the carriers by remnant spins of Ni atoms.…”

“…15,16 In the former, the excess conductivity data of sample fitted well with 2D, 3D AslamasovLarkin ͑AL͒ equations in oxygen annealed samples, which have also shown improved weak link behavior. 15 The Fluctuation induced conductivity ͑FIC͒ investigation of the latter revealed that Ni doping resulted in shifting of the crossover temperature to lower values through the scattering of the carriers by remnant spins of Ni atoms. 16 Many investigations have shown that the superconducting properties of Cu 1−x Tl x Ba 2 Ca n−1 Cu n O 2n+4−␦ ͑n =2, 3, 4, and 5͒ are usually highly sensitive to different annealing atmospheres and temperatures.…”