Ternary multicomponent Ba/Mg/Si compounds with inherent bonding hierarchy and rattling Ba atoms toward low lattice thermal conductivity

Abstract

Compositional tailoring externally enables fine-tuning of thermal transport parameters of materials by dual modulation of electronic or thermal transport properties. We theoretically investigate the lattice dynamics of three particularly ternary...

A novel 2D material with intrinsically low thermal conductivity of Ga2O3(100): first-principles investigations

“…Thus, the group velocity of acoustic phonons plays an important role in determining the lattice thermal conductivity. 49,50 As shown in Fig. 5(a) and (b), the group velocities of three acoustic branches are far higher than those of the optical modes, which is in agreement with the dispersed relation of the phonon band.…”

Theoretical and Experimental Study of CaMgSi Thermoelectric Properties

“…Figure b shows the lifetime of CaMgSi obtaining a value of 16.8 ps at acoustic branches. Li et al reported similar values of the Grüneisen parameter and lifetime for BaMgSi, Ba 2 Mg 3 Si 4 , and BaMg 2 Si 2 , identifying that they can be designed as low-thermal-conductivity materials …”

“…Li et al reported similar values of the Grüneisen parameter and lifetime for BaMgSi, Ba 2 Mg 3 Si 4 , and BaMg 2 Si 2 , identifying that they can be designed as low-thermal-conductivity materials. 32 …”

High Thermoelectric Performance Achieved in Bulk Selenium with Nanostructural Building Blocks

“…To estimate the bond interaction strength of selenium, we normalize the trace of interatomic force constant (IFC) tensor versus atomic distance , and show it in Figure . It can be seen that the nearest neighbors, separated by about 2.4 Å, have the largest interaction and are much stronger than the rest coordinated neighbor Se atoms, which is in sharp contrast to the resonant bonding feature of rocksalt IV–VI lead chalcogenides and ternary BaMgSi compounds. , From the above phenomenon we can infer that heat is easily confined in the quasi-1D (0D) Se atom chains (rings) when the system is vibrated, which leads to different heat transport mechanisms for t-Se and r-Se: the atom chain of t-Se acts like a heat transmission channel , while the Se6 ring in r-Se behaves like a heat transport fence to impede thermal transport, which induce obvious phonon–phonon scattering and consequently the reduced lattice thermal conductivity.…”

“…To estimate the bond interaction strength of selenium, we normalize the trace of interatomic force constant (IFC) tensor versus atomic distance 68,69 and show it in Figure 7. It can be seen that the nearest neighbors, separated by about 2.4 Å, have the largest interaction and are much stronger than the rest coordinated neighbor Se atoms, which is in sharp contrast to the resonant bonding feature of rocksalt IV−VI lead chalcogenides and ternary BaMgSi compounds.…”