Searching and designing materials with intrinsically low lattice thermal conductivity （LTC） have attracted extensive considera- tion in thermoelectrics and thermal management community. The concept of part-crystalli...Searching and designing materials with intrinsically low lattice thermal conductivity （LTC） have attracted extensive considera- tion in thermoelectrics and thermal management community. The concept of part-crystalline part-liquid state, or even part-crystalline part-amorphous state, has recently been proposed to describe the exotic structure of materials with chemical-bond hierarchy, in which a set of atoms is weakly bonded to the rest species while the other sublattices retain relatively strong rigidity. The whole system inherently manifests the coexistence of rigid crystalline sublattices and fluctuating noncrystalline substructures. Representative materials in the unusual state can be classified into two categories, i.e., caged and non-caged ones. LTCs in both systems deviate from the traditional 7-1 relationship （T, the absolute temperature）, which can hardly be described by small-parameter-based perturbation approaches. Beyond the classical perturbation theory, an extra rattling-like scattering should be considered to interpret the liquid-like and sublattice-amorphization-induced heat transport. Such a kind of compounds could be promising high-performance thermoelectric materials, due to the extremely low LTCs. Other physical properties for these part-crystalline substances should also exhibit certain novelty and deserve further exploration.展开更多
基金the National Key Basic Research Program of China(Grant No.2013CB632501)the National Natural Science Foundation of China(Grant Nos.11234012+1 种基金51121064 and 51572167)the Science and Technology Commission of Shanghai Municipality(Grant Nos.14DZ2261200 and 15JC1400301)
文摘Searching and designing materials with intrinsically low lattice thermal conductivity （LTC） have attracted extensive considera- tion in thermoelectrics and thermal management community. The concept of part-crystalline part-liquid state, or even part-crystalline part-amorphous state, has recently been proposed to describe the exotic structure of materials with chemical-bond hierarchy, in which a set of atoms is weakly bonded to the rest species while the other sublattices retain relatively strong rigidity. The whole system inherently manifests the coexistence of rigid crystalline sublattices and fluctuating noncrystalline substructures. Representative materials in the unusual state can be classified into two categories, i.e., caged and non-caged ones. LTCs in both systems deviate from the traditional 7-1 relationship （T, the absolute temperature）, which can hardly be described by small-parameter-based perturbation approaches. Beyond the classical perturbation theory, an extra rattling-like scattering should be considered to interpret the liquid-like and sublattice-amorphization-induced heat transport. Such a kind of compounds could be promising high-performance thermoelectric materials, due to the extremely low LTCs. Other physical properties for these part-crystalline substances should also exhibit certain novelty and deserve further exploration.
