Thermal conductivity of ferromagnetic metallic La_0.95Ag_0.05MnO₃manganites: role of carrier, spin waves and lattice–impurity scattering

Abstract

2015): Thermal conductivity of ferromagnetic metallic La 0.95 Ag 0.05 MnO 3 manganites: role of carrier, spin waves and lattice-impurity scattering, Molecular Simulation,The lattice contribution to the thermal conductivity (k ph ) of La 0.95 Ag 0.05 MnO 3 manganites is theoretically analysed within the framework of Kubo model. The theory is formulated when thermal conduction is limited by the scattering of phonons from defects, grain boundaries, charge carriers, spin waves and phonons. The lattice thermal conductivity dominates in Ag-doped manganites and is artefact of strong phonon -impurity and phonon-phonon scattering mechanism in the ferromagnetic metallic state. The electronic contribution to the thermal conductivity (k e ) is estimated following the Wiedemann-Franz law. Another important contribution in the metallic phase should come from spin waves (k m ). It is noticed that k m increases with a T 2 dependence on the temperature. The behaviour of the thermal conductivity in manganites is determined by competition among the several operating scattering mechanisms for the heat carriers and a balance between electron, magnon and phonon contributions.