Pre-Onset, Transitional, and Foot Regions in Resistance Versus TemperatureBehavior in High-T (sub 2) Cuprates: Inferences Regarding Maximum T (sub 2)

摘要

We have studied the pre-onset deviation-from-linearity region, the transitionalregime, and the foot region in the resistance versus temperature behavior of high-T sub c oxdie superconductors, employing time varying magnetic fields and carefully controlled precise temperatures. We have shown that the best value of T sub c can be extrapolated from the magnetic field induced divergence of the resistance versus inverse absolute temperature data as derived from the transitional and/or foot regions. These data are in accord with results from previous Hall effect studies. The pre-onset region however, shows a differing behavior (in R versus 1000/T as a function of B) which we believe links it to an incipient Cooper pairing that suffers a kinetic barrier opposing formation of a full supercurrent. This kinetic dependence is believed to be associated with the lifetime of the mediator particle. This particle is interpreted to be the virtual exciton formed from internal-field induced charge-transfer excitations which transiently neutralize the multivalence cations and establish bound holes on the oxygens.