Study of CuO Nano-particles/CuTl-1223 Superconductor Composite
- PDF / 1,292,502 Bytes
- 20 Pages / 439.37 x 666.142 pts Page_size
- 34 Downloads / 180 Views
Study of CuO Nano-particles/CuTl-1223 Superconductor Composite M. Mumtaz · Asif I. Bhatti · K. Nadeem · Nawazish A. Khan · Abida Saleem · S. Tajammul Hussain
Received: 1 August 2012 / Accepted: 11 September 2012 / Published online: 27 September 2012 © Springer Science+Business Media, LLC 2012
Abstract Synthesis and characterization of (CuO)x /Cu0.5 Tl0.5 Ba2 Ca2 Cu3 O10−δ ; {(CuO)x /CuTl-1223} composites with x = 0 %, 10 %, 15 % and 20 % have been reported. The fluctuations induced conductivity (FIC) analysis of (CuO)x /CuTl1223 composite has been carried out using Aslamazov-Larkin (AL) and LawrenceDoniach (LD) models in the temperature regime well above the critical temperature (T > Tc ). The electrical resistivity versus temperature curves of as-prepared and oxygen post-annealed (CuO)x /CuTl-1223 composite were fitted by using above mentioned models to extract the microscopic parameters such as zero temperature coherence length along c-axis{ξc (0)}, inter-layer coupling (J ), dimensional critical exponent (λ) and inter-grain coupling constant (α) etc. It has been observed that the cross-over temperature (To ) fits very well the two-dimensional (2D) and threedimensional (3D) AL equations and shifts towards the lower temperature regime with the enhanced weight percentage of CuO nano-particles. The shifting of AL 3D region to higher temperature after oxygen post-annealing indicates the restoration of oxygen and optimization of charge carriers in conducting CuO2 planes. The gradual decrease in the value of inter-grain coupling constant (α) with the increase of CuO nano-particles content reflects an improvement in the inter-grain coupling resulting into an increase in the coherence length (ξc ) along the c-axis. Almost all M. Mumtaz () · A.I. Bhatti · K. Nadeem Materials Research Laboratory, Department of Physics, International Islamic University (IIU), Islamabad 44000, Pakistan e-mail: [email protected] N.A. Khan Materials Science Laboratory, Department of Physics, Quaid-i-Azam University (QAU), Islamabad 45320, Pakistan A. Saleem · S.T. Hussain Nano Science & Catalysis Division, National Center for Physics, Shadhara Valley Road, Quaid-i-Azam University Campus, Islamabad 45320, Pakistan
186
J Low Temp Phys (2013) 170:185–204
superconductivity parameters have been improved after oxygen post-annealing. The suppression of superconductivity parameters in the composite with x = 20 % limits the optimum doping level of CuO nano-particles in (CuO)x /CuTl-1223 composite. Keywords (CuO)x /CuTl-1223 composite · CuO nano-particles · Fluctuations induced conductivity · Oxygen post-annealing
1 Introduction The synthesis of nano-particles/superconductors composites has become a novel approach in the area of advance research in superconductivity. The discovery of CuB2 Can−1 Cun O2n+4−δ [Cu-12(n − 1)n]; (n = 1, 2, 3, . . .) high temperature superconductor family has great importance due to its nontoxicity and high superconducting properties [1]. These compounds have high zero resistivity critical temperature {Tc (R = 0) > 117
Data Loading...
