Systematic induction of superconductivity in Y1-xCaxBa2Cu3O6.3 system

V. P. S. Awana; Anurag Gupta; M. A. Ansari; S. B. Samanta; R. B. Saxena; H. Kishan; Devendra Buddhikot; S. K. Malik; V. Ganesan; A. V. Narlikar

arXiv · cond-mat/0403230

Systematic induction of superconductivity in Y1-xCaxBa2Cu3O6.3 system

V. P. S. Awana·Anurag Gupta·M. A. Ansari·S. B. Samanta·R. B. Saxena·H. Kishan·Devendra Buddhikot·S. K. Malik·V. Ganesan·A. V. Narlikar

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Abstract

Compounds of series YBa2Cu3O7-d (d = 0.7), being synthesized by solid-state synthesis route with x = 0.0, 0.10, 0.15 and 0.20, crystallize in single-phase form with tetragonal structure (space group P4/mmm). The c-lattice parameter increases with increasing x, indicating successful substitution of Y3+ by bigger Ca2+ ion. Resistance versus temperature (R vs. T) measurements show that pristine sample (x = 0.0) is semiconducting down to 5 K. Induction of superconductivity is seen with an increase in x. The x = 0.10 sample exhibit the onset of superconducting transition (Tconset) at around 42 K without attaining zero resistance superconducting transition temperature (TcR=0) state down to 5 K. For x = 0.15 and 0.20 samples TcR=0 is observed at 25 K and 35 K with Tconset of 52 K and 61 K respectively. Thermo-electric power (S) measurements in temperature range of 5 - 300 K, exhibited TcS=0 at around 25 K and 35 K respectively for x = 0.15 and 0.20 samples. Further a sign change in S from +ve to -ve is observed at low temperatures for x = 0.0 sample. Room temperature +ve S value decreases with increase in x, indicating enhanced number of mobile holes. The Magneto-transport measurements under applied magnet ic fields of 3 and 6 Tesla show the broadening of superconducting transition for x = 0.15, and 0.20 samples. For x = 0.10 sample the superconducting transition is suppressed in applied fields of 3 and 6 Tesla. Our results will help in constructing the complete phase diagram of Y1-xCaxBa2Cu3O7-d compounds with various x and d.

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V. P. S. Awana, Anurag Gupta, M. A. Ansari, S. B. Samanta, R. B. Saxena, H. Kishan, Devendra Buddhikot, S. K. Malik, V. Ganesan, A. V. Narlikar. 2004-03-09. Systematic induction of superconductivity in Y1-xCaxBa2Cu3O6.3 system. https://arxiv.org/abs/cond-mat/0403230

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