Phonon-induced superconductivity and physical properties in intercalated fullerides Rb3C60
محورهای موضوعی : Journal of Theoretical and Applied PhysicsDinesh Varshney 1 , Rajendra Jain 2 , Namita Singh 3
1 - Materials Science Laboratory, School of Physics, Vigyan Bhawan, Devi Ahilya University
2 - Materials Science Laboratory, School of Physics, Vigyan Bhawan, Devi Ahilya University
3 - Department of Physics, Ranchi College, Ranchi University Ranchi
کلید واژه: Fullerenes, Inter, and intra, molecular phonons, Transition temperature, Carbon isotope effect, Energy gap ratio,
چکیده مقاله :
AbstractThe nature of electron pairing mechanism and physical properties leading to superconducting state and normal state resistivity in alkali metal (Rb) intercalated fullerenes are explored. Keeping in mind that free electrons in lowest molecular orbital are coupled with inter-molecular phonons, the coupling with inter-molecular phonon leads to transition temperature (Tc) of about 4.17 K. The electrons also couple with the intra-molecular phonons. Within the framework of strong coupling theory, Tc is estimated at 34 K. The carbon isotope effect exponent, the energy gap ratio, influence of pressure and volume on Tc, and thermodynamical parameters describing the superconducting state confer that Rb3C60 as s-wave superconductor. Estimated contribution to resistivity using scattering with inter- and intra-molecular phonon, when subtracted from single crystal data, infers quadratic temperature dependence over most of the temperature range and is attributed to electron–electron inelastic scattering. Both low frequency intermolecular and high frequency intra-molecular phonons have significant bearing in Rb3C60 superconductor.
