Abstract
Lattice thermal conductivity (k(latt)) is an important physical parameter for understanding the thermal transport and dynamics evolution. Here, we calculate(k(latt)) of alkaline earth metal oxides (MOs, M = Be, Mg, Ca, Sr, Ba) by first principles calculations combined with lattice dynamics theory. Our results indicate that the magnitudes of (k(latt)) of MOs at ambient conditions are closely related to the atomic masses of metal atoms, that is, the lighter atomic masses of metals in MOs possess the larger (k(latt)), which is consistent with the order of alkaline earth metals in Periodic Table. Under high pressure, (k(latt)) of MOs show linearly increase as a function of pressure; meanwhile, the pressure dependence of (k(latt)) is relatively larger for MOs with lighter atomic masses. The calculations show that the structural phase transitions of MOs lead to obvious reductions in (k(latt)) due to the giant variations in scattering rates. By contrast, the effect of phase transition on elastic property and wave velocities are weak, which implies the variation of group velocities are faintly effect on (k(latt)).
NSTL
Elsevier