Thèses

Jeudi 5 Octobre 2017 à 14h00.

Transport Thermique aux Interfaces : Angle Critique des Phonons, Transfert à Travers un Gap ; Transfert Autour d’une Nanoparticule Colloïdale Cœur-Coquille

''This thesis is devoted to the study of interfacial thermal transport at the nanoscale where Fourier’s law becomes violated. At this scale, the phonon mean free paths become smaller than the characteristic length of the system, and heat transfer is no longer diffusive but rather ballistic. As a consequence, the thermal boundary resistance (TBR) becomes the determinant factor in heat transfer as phonons are experiencing a lot of collisions with the boundaries compared to phonon-phonon collisions. The goal of this thesis is, firstly, to characterize the spectral and angular phonon transmission and predict the thermal boundary conductance (the inverse of the thermal boundary resistance) at the interface between two solids; secondly, to quantify the phononic contribution in heat transfer across a nanometric vacuum gap that sep- arates two solids; and finally, to investigate heat transfer in a system made of a core-shell nanoparticle (NP) immersed in water and heated by a laser pulse.''