Thermoelectric properties of La0.9CoFe3Sb12–CoSb3 skutterudite nanocomposites

Abstract

A hydrothermal nanoparticle-plating technique has been employed in order to grow a layer of CoSb3 nanoparticles on the surface of La0.9CoFe3Sb12 bulk matrix grains. The nanoparticles have a typical size of 30–40 nm while the nano-layer can be up to several hundreds of nanometer thick. The nanoparticle layer, which resides at the grain boundary after hotpressing, provides an extra scattering channel for phonons, in addition to the “rattler” atoms (La), grain boundary scattering, and mass fluctuation mechanisms found within the bulk matrix grain. The electrical resistivity, thermopower, thermal conductivity, and Hall coefficient have been investigated as a function of temperature and the weight percentage (%) of nanoparticles. Largely due to the reduced lattice thermal conductivity, a ZT value of ∼0.5 is attained at 725 K on the sample with 5 wt % of nanoparticles showing a 15% improvement of the ZT from that of the sample without nanoparticles and comparable to the best value reported at this temperature.

High-temperature electrical and thermal transport properties of fully filled skutterudites RFe4Sb12 (R = Ca, Sr, Ba, La, Ce, Pr, Nd, Eu, and Yb)

“…Furthermore, the ZT values in p-type filled skutterudites are confirmed in experiment around 1.0, much lower than n-type materials. [21][22][23] The stagnation of low ZT value in p-type skutterudites limits the further development of thermoelectric modules and devices, since both excellent n-and p-type materials are required for high efficiency thermoelectric technology. Therefore, searching for p-type skutterudites with comparable ZT values to n-type materials is urgent for real industry applications.…”

Waste Thermal Energy Harvesting (I): Thermoelectric Effect

“…These techniques can be used to make samples with a relatively low-cost at large scale [319], which have been applied to many other thermoelectric materials including PbTe [320,321] and skutterudites [322][323][324]. However, a major challenge of this approach is the removal of the binders or organic agents used in the grinding, milling or wet-chemistry processes.…”

On the Way to the Creation of Thermoelectric Converters on the Basis of Nanoobjects Such as Quantum Dots, Nanowires and Superlattices

“…Тому останнім часом основна увага дослідників зосередилася на вивченні об'ємних нанокомпозитів, оскільки вна-слідок наноструктурування було виявлене помітне покращення термоелектричних характеристик [40,54,[64][65][66][67][68][69]. Наноструктурування матеріалу, по-перше, може збільшити густину станів поблизу рівня Фермі і тим самим підвищити електропро-відність; по-друге, може привести до локального збільшення ефективної маси електронів, а отже, підвищити коефіцієнт Зеєбека [13]; по-третє, як-що об'ємний зразок складається з нанорозмірних зерен, то це може збільшити розсіяння фононів на їх границях і таким чином зменшити теплопро-відність [70][71][72][73].…”