Dielectric Properties of CUO.5 Tlo.5 Ba2 Ca2 CU3-x Mx 010-3 ( M = Cd, Zn, Ni : x = 0, 1. 5) Superconductors.

Abstract

We have synthesized Cuo,sTlo.sBa2 CazCuJOIU.(i and Cuo.sTlo,58az CaZCuI SOIO-n (M=Cd, Zn, Nil superconduct ing samples. The samples were synthesized by two step solid state reaction method. We have studied diel ectric properti es of lhese samples at low frequency. The main objecti ves of these studies were to investigate the ro le of Cd. Zn. and Ni doping in our superconductors (HTSC). We have measured dielectric constants (£' and 6"), di e lectric loss (lana) and ae conductivity (ane). In the resistivity measurements these samples have shown metallic variations of resistivity from room temperature down to onset o f superconductivity. The onset of superconductivity in ClIo,sTlo.sBaz Ca2CU30 W-lI and Cuo.s Tln.sBa2 Ca2CULsM 1.50 10..0 (M=Cd, Zn, Nil samples are observed at 105.6, 101.7, 11 4, 106.3 K and Ol at 98.3 , 95.4, 102.3, 102K respectively. The negati ve capacitance is observed in our Cuo.sTlo.sBa2 C,12CU3010-ti and Cuo.sTlu.sBa2 Ca2Cul.s010-6 (M=Cd, Zn, Ni) superconducting samples. We observed that di electric propel1ies of Cuo.sTlo.5Ba2 Ca2CU30lU-ll and Cuo.sTIIJ.5Baz Ca2CUuOIO-II (M=Cd, Zn_ Ni) superconducling samples depends on temperature ancl frequency or electric field.