Thermoelectric power of metallic Rb3C60: phonon-drag and carrier diffusion contributions
الموضوعات : Journal of Theoretical and Applied PhysicsDinesh Varshney 1 , Namita Singh 2
1 - Materials Science Laboratory, School of Physics, Vigyan Bhawan, Devi Ahilya University
2 - Department of Physics, Ranchi College, Ranchi University Ranchi
الکلمات المفتاحية: RbC, Thermoelectric power, Phonon drag, Carrier diffusion, Intermolecular phonon,
ملخص المقالة :
AbstractThermoelectric power (S) of Rb3C60 fullerides in the metallic phase is theoretically estimated. We first develop a Hamiltonian model that incorporates the scattering rates within the relaxation time approximation to estimate the phonon-drag thermoelectric power (Sphdrag) incorporating the scattering of phonons with defects, electrons as carriers, grain boundaries, and phonon-phonon interactions. As a next step, Mott expression within parabolic band approximation is used to analyze the electron diffusive thermoelectric power (Scdiff) using Fermi energy as electron parameter, and Scdiff shows a linear temperature dependence. The Sphdrag is nonzero in both normal and superconducting states. Its behavior is determined by competition among the several operating scattering rates for heat carriers and a balance between diffusive carrier and phonon-drag contributions. Acoustic phonons are effectively scattered by various scatterers for the thermoelectric power. S infers a change in slope above transition temperature and becomes almost linear above 70 K.
