First-principles study of electron-phonon coupling factor and lattice thermal conductivity of L12 type alloys

We calculated electron-phonon coupling factors and lattice thermal conductivity of FCC metals and L12 type binary alloys (X3Y: X,Y = Cu, Ag, Au, Pt, Pd) by using first-principles calculations. The electron-phonon coupling factors of Ag- and Au-based L12 type alloys are much lower than that of Pd- and Pt-based alloys because of the low density of states around Fermi level of Ag- and Au-based alloys. The lattice thermal conductivities of Au-based L12 type alloys are lower than Pd-, Pt-based alloys and other alloys because of their heavy atomic mass of Au and low force constants. We also evaluated the interfacial electron-phonon thermal resistance of a metal/insulator bilayer originated from non-equilibrium state between electrons and phonons when L12 type alloys are used as a metal layer. The interfacial electron-phonon thermal resistance of Ag- and Au-based L12 type alloys is much larger than the others as a consequence of the low electron-phonon coupling factor and the low lattice thermal conductivity.