Accession Number : ADA258175


Title :   The Pre-Onset, Transitional, and Foot Regions in Resistance Versus Temperature Behavior in High-T sub 2 Cuprates: Inferences Regarding Maximum T sub 2


Descriptive Note : Final rept.


Corporate Author : ARMY LAB COMMAND WATERTOWN MA MATERIALTECHNOLOGY LAB


Personal Author(s) : Vezzoli, G C ; Burke, T ; Chen, M F ; Craver, F ; Stanley, W


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a258175.pdf


Report Date : Sep 1992


Pagination or Media Count : 25


Abstract : We have studied the pre-onset deviation-from-linearity region, the transitional regime, 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.


Descriptors :   *TEMPERATURE , *RESISTANCE , *HALL EFFECT , *SUPERCONDUCTIVITY , *COPPER COMPOUNDS , FUNCTIONS , CALCIUM , SUPERCONDUCTORS , TIME , PARTICLES , INTERNAL , BARIUM , GADOLINIUM , TRANSFER , VALUE , KINETICS , CHARGE TRANSFER , BARRIERS , LINEARITY , COPPER , FLUX DENSITY , THALLIUM , BISMUTH , YTTRIUM , EXCITONS , STRONTIUM , OXIDES , OXYGEN , REGIONS , EXCITATION , MAGNETIC FIELDS , CATIONS , DENSITY


Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Electricity and Magnetism
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE