Intrinsically low thermal conductivity from a quasi-one-dimensional crystal structure and enhanced electrical conductivity network via Pb doping in SbCrSe3
Bibliographic record
Abstract
The development of new routes for the production of thermoelectric materials with low-cost and high-performance characteristics has been one of the long-term strategies for saving and harvesting thermal energy. Herein, we report a new approach for improving thermoelectric properties by employing the intrinsically low thermal conductivity of a quasi-one-dimensional (quasi-1D) crystal structure and optimizing the power factor with aliovalent ion doping. As an example, we demonstrated that SbCrSe3, in which two parallel chains of CrSe6 octahedra are linked by antimony atoms, possesses a quasi-1D property that resulted in an ultra-low thermal conductivity of 0.56 W m−1 K−1 at 900 K. After maximizing the power factor by Pb doping, the peak ZT value of the optimized Pb-doped sample reached 0.46 at 900 K, which is an enhancement of 24 times that of the parent SbCrSe3 structure. The mechanisms that lead to low thermal conductivity derive from anharmonic phonons with the presence of the lone-pair electrons of Sb atoms and weak bonds between the CrSe6 double chains. These results shed new light on the design of new and high-performance thermoelectric materials. A material that is counter-intuitively both a good electrical conductor and thermal insulator has been made by a team in China and the USA. The ideal thermoelectric material would have a high electrical conductivity and a low thermal conductivity. But this is challenging as both properties are facilitated by electrons. Now, Guoyu Wang (Chinese Academy of Sciences), Tao Yang, Xiaoyuan Zhou (Chongqing University) and their colleagues present an idea for seeking and optimizing low-dimensional thermoelectric materials. They started with a material with an intrinsically low thermal conductivity due to its atomic structure — the atoms in SbCrSe3 form one-dimensional chains held together by weak bonds, which inhibits thermal conduction. They then boosted the material's electrical conductivity by adding lead atoms. This approach could be applied to other materials with a similar one-dimensional atomic structure. SbCrSe3, described as a quasi-1D structure with CrSe6 double chains, possesses an intrinsic low thermal conductivity due to the large anharmonicity and weak chemical bonds. By substituting Sb with Pb, a peak ZT= 0.46 at 900 K is obtained in Pb0.05Sb0.95CrSe3 sample. This is about 24 times larger value than measured on pristine SbCrSe3.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".