caa a22 4500 44538056X CHVBK 20180317143016.0 cr unu---uuuuu 170323e20110501xx s 000 0 eng 10.1007/s10948-010-0827-4 doi (NATIONALLICENCE)springer-10.1007/s10948-010-0827-4 RETRACTED ARTICLE: AC-field Frequency Response ofCu0.5Tl0.5Ba2(Ca2− q Mg q )Cu3O10− δ Bulk Superconductor [Elektronische Daten] [A. Younis, A. Hussain, M. Asghar, A. Manzoor, S. Javed] The dielectric properties of Cu0.5Tl0.5Ba2Ca2−q MgqCu3O10−δ (q=0, 0.5, 1.0 1.5) superconductor samples were studied at two temperatures of 80 and 290 K by capacitance (C) and conductance (G) measurements with the test frequency (f) in the range of 10 KHz to 10 MHz. We have presented the measurements of the dielectric constants (ε′ and ε″), dielectric loss factor (tan δ) and ac-conductivity (σ ac) as a function of frequency and temperature. A negative capacitance (NC) experience has been observed, which is most likely due to different contact electrodes and superconductor samples' Fermi levels. Since metals have their Fermi levels higher than ceramics, there is a flow of the carriers from the ceramic samples towards the metal electrodes. The dielectric polarization phenomenon is observed, which is due to dislodgment of mobile charges from their equilibrium position relative to fixed charges of the reservoir layer. The improved inter plane coupling promoted by Mg substitution at Ca site would change the dielectric response of Cu0.5Tl0.5Ba2Ca2−q MgqCu3O10−δ superconductors. To observe such effects in Mg doped Cu0.5Tl0.5Ba2Ca2−q MgqCu3O10−δ superconductors, di- electric measurements were carried out both at room temperature (290 K) and in the superconducting state closer to the boiling point of liquid nitrogen (80 K). The excess conductivity arising due to superconducting state of material has been determined, and its role in the mechanism of superconductivity is suggested. The negative dielectric constant (ε′) and dielectric loss factor (tan δ) show strong dispersion at low frequencies. The lower thermal agitation at 80 K may enhance the polarizability and hence the dielectric constants (ε′ and ε″). Springer Science+Business Media, LLC, 2010 Cu0.5Tl0.5Ba2Ca2− q Mg q Cu3O10− δ superconductors nationallicence Dielectric constant nationallicence Polarization nationallicence Capacitance and conductance nationallicence Younis A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut Hussain A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut Asghar M. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut Manzoor A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut Javed S. Engineering Laboratory Department of Electrical Engineering, FUUAST, Islamabad, Pakistan aut Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/4(2011-05-01), 1327-1332 1557-1939 24:4<1327 2011 24 10948 https://doi.org/10.1007/s10948-010-0827-4 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10948-010-0827-4 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Younis A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut NATIONALLICENCE 700 1- Hussain A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut NATIONALLICENCE 700 1- Asghar M. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut NATIONALLICENCE 700 1- Manzoor A. Material Science Laboratory Department of Physics, Quaid-i-Azam University, 45320, Islamabad, Pakistan aut NATIONALLICENCE 700 1- Javed S. Engineering Laboratory Department of Electrical Engineering, FUUAST, Islamabad, Pakistan aut NATIONALLICENCE 773 0- Journal of Superconductivity and Novel Magnetism Springer US; http://www.springer-ny.com 24/4(2011-05-01), 1327-1332 1557-1939 24:4<1327 2011 24 10948 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer