Observation of Vortex Lattice Related Anomalies in Polycrystalline YBa<sub>2</sub>Cu<sub>3</sub>O<sub>7-x</sub> Near the Superconducting Transition
- 1 Institute of Physics, Bhubaneswar, India
Abstract
The d.c. I-V characteristic of polycrystalline YBa 2 Cu 3 O 7-x high temperature superconductors (HTSC) is measured near the transition temperature (T c ). The T c was found to be 90 K with a width of 2 K. The voltage was measured at various current values and with reversing the current. A difference in voltage was found for forward and reverse current directions near T c . The observed directionality of the I-V characteristic can be understood in terms of quantized magnetic flux by the self-field of the current and the proximity junctions in these materials. This can also be understood qualitatively as due to the d-wave superconductivity. The measured dc voltage showed increased noise near T c which is possibly related to 1/f noise due to the motion of Abrikosov flux lines.
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