Highly enhanced thermal stability of Zn4Sb3 nanocomposites

Abstract

The effects of nano-sized TiO2 and ZnO ceramic inclusions on the high temperature stability of Zn4Sb3 have been studied using multi-temperature synchrotron powder X-ray diffraction. Samples with 9 nm TiO2 nanoinclusions exhibit remarkable stability after three heating cycles to 625 K.

In Operando Study of High‐Performance Thermoelectric Materials for Power Generation: A Case Study of β‐Zn4sb3

“…The TiO2 nanocomposite sample showed significant improvement in thermal stability by retaining 98.8 wt% of the original phase after heating to 625 K, compared with 42 wt% degradation in the pure sample [26] . Although remarkable results have been obtained both respect to the TE performance and the thermal stability at high temperatures, there is virtually no report on the practical use of Zn4Sb3 in TEGs, and the reason for this is still unknown.…”

“…The results showed that these doped samples are more stable than the non-doped sample under thermal cycling and during heat treatment. With the purpose of blocking the Zn diffusion inside Zn4Sb3, nano-sized ZnO and TiO2 ceramic inclusions have also been investigated [26] .…”

“…In addition, all previous study was only carried out using indirect experiment e.g. TE properties or in-situ powder X-ray diffraction in certain temperature or small (less than 10 K for Seebeck measurement) temperature gradient conditions [11,[21][22][23][24][25][26] . In fact, pressed pellet TE element operates under conditions of power generating and large temperature gradients in TEG.…”

“…Besides increasing the zT, many studies have also been conducted to investigate the thermal stability of this material [11,[21][22][23][24][25][26] . Caillat et al have shown that TE properties of Zn4Sb3 are stable up to 670 K under argon and static vacuum, but unstable in the dynamic vacuum due to the evaporation of Sb at temperatures higher than 543 K resulting in an increased electrical resistivity [11] .…”

“…The decomposition of the Zn4Sb3 phase has been studied quantitatively using synchrotron powder X-ray diffraction (PXRD) [22][23][24][25][26] as well as by extensive evaluation of physical properties [27,28] . Attempts have also been made to substitute the Zn-sites with various elements such as Mg [22] , Cd [23,24,29] , and Pb [25] .…”