The Effect of Potassium Doping on Resistive Transitions and Transport Critical Current of Bulk YBCO high-Tc Superconductors

Authors : S ÇELEBİ, A ÖZTÜRK, İ KARACA, U KÖLEMEN

Pages : 567-576

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Publication Date : 0000-00-00

Article Type : Research Paper

Abstract :We report on observations of the effect of potassium in YBCO insert ignore into journalissuearticles values(123); high temperature superconductors with nominal composition Y\insert ignore into journalissuearticles values( 1-0,2x \); Ba\insert ignore into journalissuearticles values( 2-0.2x \); K\insert ignore into journalissuearticles values( x \); Cu\insert ignore into journalissuearticles values( 3 \); O\insert ignore into journalissuearticles values( y \);. The electrical resistivity measurements show that the critical temperature Tc \); insert ignore into journalissuearticles values(R=0); shifted slightly to lower temparature due to the K doping process. This process also decreases the transport critical current density and the activation energy for thermally activated flux flow. The magnetic field dependence of \insert ignore into journalissuearticles values( jc \); was measured at 77 K after zero field cooling insert ignore into journalissuearticles values(ZFC); when the applied magnetic field is impressed insert ignore into journalissuearticles values(ZFCV); and removed insert ignore into journalissuearticles values(ZFCD);. The results are discussed in terms of ``return`` magnetic flux density associated with the magnetization of the grains. Activation energy was determined from the Arrhenius resistivity plot versus temperature curve. The XRD patterns are also presented for sample characterization.
Keywords : High Tc superconductors, K doping, critical current density, resistive transition