Accession Number : ADA266749


Title :   Fullerene Superconductors


Descriptive Note : Final rept. 15 May 92-14 Mar 93,


Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF CHEMISTRY AND BIOCHEMISTRY


Personal Author(s) : Kaner, Richard B


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a266749.pdf


Report Date : 17 Jun 1993


Pagination or Media Count : 2


Abstract : The electrical, magnetic and optical properties of the fullerene superconductors K3C60 and Rb3C60 have been investigated. The room temperature microwave resistivity at 60 GHz of pressed powder samples of K3C60 is approximately 5m (ohms) cm. The resistivity drops by almost one order of magnitude on cooling to 20K, indicative of metallic behavior, before the samples superconduct at T (sub) c = 19.3K. Optical reflectivity spectra are consistent with metallic materials. An extrapolation of the frequency dependence of conductivity leads to d.c. conductivities of 1.3 x 10 (exp 3) (ohm)-l and 1.2 x 10 (exp 3) (ohm)-l for K3C60 and Rb3C60, respectively. The gap values A of 24 / cm for K3C60 and 30 /cm for Rb3C60 are consistent with weak-coupling and a BCS singlet ground state. Upper critical fields of 28-30 Tesla for K3C60 and 38-55 Tesla for Rb3C60 have been measured. The lower values are from static magnetic experiments, while the upper values used pulsed magnets.


Descriptors :   *SUPERCONDUCTORS , *FULLERENES , FREQUENCY , METALS , OPTICAL PROPERTIES , TEMPERATURE , COOLING , ROOM TEMPERATURE , PULSES , RUBIDIUM , EXTRAPOLATION , COUPLINGS , POTASSIUM , STATICS , MAGNETS , REFLECTIVITY , GROUND STATE , DROPS , SPECTRA , ELECTRICAL PROPERTIES , MICROWAVES , MAGNETIC PROPERTIES , CONDUCTIVITY , MATERIALS , POWDERS


Subject Categories : Inorganic Chemistry
      Electricity and Magnetism
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE