Compositionally Engineered Non-Equimolar LaCoO3-Based High-Entropy Perovskites with Enhanced Thermoelectric Performance
Abstract
The decoupling of phonon and electron transport remains a central challenge in the development of high-performance TE materials. Configurational-entropy maximization is widely invoked as a design principle for decoupling phonon and electron transport. This study investigates compositionally engineered LaCoO3-based high-entropy perovskites to determine whether thermoelectric transport can be improved by tuning cation identity and concentration rather than maximizing configurational entropy. La1−xSrx(CoFeMnCrNi)O3 (x=0.0--$0.2$) and selected non-equimolar A- and B-site perovskite compositions were prepared by solid-state reaction. The obtained samples are predominantly single-phase, as confirmed by X-ray diffraction and Rietveld refinement, consistent with the calculated size-disorder parameters. Multication disorder introduces substantial mass and strain-field fluctuations that promote phonon scattering. All samples exhibit p-type, thermally activated electrical transport consistent with adiabatic SPH. Sr substitution progressively reduces the hopping barrier and ρ, whereas non-equimolar B-site engineering partially recovers electrical transport while retaining low k. La0.9Sr0.1Co0.4Cr0.3Ni0.1Fe0.1Mn0.1O3, featuring a Co-rich and Cr-rich B-site composition, combines Co-associated mixed valence and spin-state degeneracy that sustain a large alpha with Cr-mediated control of carrier concentration and a reduced polaron hopping barrier of 0.19eV. This composition achieves a power factor of 40--43 μW/(m K2) and a zT∼0.072 at 1100K, approximately 2.7 times that of its equimolar analogue. These results demonstrate that targeted cation chemistry and mass contrast, rather than configurational-entropy maximization alone, provide an effective strategy for balancing electronic and phonon transport in multicomponent oxide TE.
Related
- Enhanced thermoelectric performance of Bi 2 Te 2.7 Se 0.3 through microstructural engineering and powder processing design
- Defect chemistry engineering of cobalt-free La–Sr–Fe–Ni–O perovskites for high-performance solid oxide cell air electrodes
- Transport statistics and thermoelectric performance of Hofstadters butterfly
- Engineering Giant Thermoelectric Performance through Electrode-Coupling Geometry and Magnetic Flux in Quasiperiodic Su-Schrieffer-Heeger Rings
- Frustrated Gd3+ Double Perovskites as High-Performance Magnetocaloric Materials for Sub-100 mK Adiabatic Demagnetization Refrigeration
BibTeX
@misc{kumar2026compositionally,
title = {{Compositionally Engineered Non-Equimolar LaCoO$_3$-Based High-Entropy Perovskites with Enhanced Thermoelectric Performance}},
author = {Jitendra Kumar and David Bérardan and Diana Dragoe and Nita Dragoe and Ashutosh Kumar},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2609.28155},
eprint = {2609.28155},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2609.28155},
}
RIS
TY - UNPB
TI - Compositionally Engineered Non-Equimolar LaCoO_3-Based High-Entropy Perovskites with Enhanced Thermoelectric Performance
AU - Jitendra Kumar
AU - David Bérardan
AU - Diana Dragoe
AU - Nita Dragoe
AU - Ashutosh Kumar
PY - 2026
DA - 2026/09/23
PB - arXiv
DO - 10.48550/arxiv.2609.28155
UR - https://arxiv.org/abs/2609.28155
AB - The decoupling of phonon and electron transport remains a central challenge in the development of high-performance TE materials. Configurational-entropy maximization is widely invoked as a design principle for decoupling phonon and electron transport. This study investigates compositionally engineered LaCoO_3-based high-entropy perovskites to determine whether thermoelectric transport can be improved by tuning cation identity and concentration rather than maximizing configurational entropy. La_1−xSr_x(CoFeMnCrNi)O_3 (x=0.0--$0.2$) and selected non-equimolar A- and B-site perovskite compositions were prepared by solid-state reaction. The obtained samples are predominantly single-phase, as confirmed by X-ray diffraction and Rietveld refinement, consistent with the calculated size-disorder parameters. Multication disorder introduces substantial mass and strain-field fluctuations that promote phonon scattering. All samples exhibit p-type, thermally activated electrical transport consistent with adiabatic SPH. Sr substitution progressively reduces the hopping barrier and ρ, whereas non-equimolar B-site engineering partially recovers electrical transport while retaining low k. La_0.9Sr_0.1Co_0.4Cr_0.3Ni_0.1Fe_0.1Mn_0.1O_3, featuring a Co-rich and Cr-rich B-site composition, combines Co-associated mixed valence and spin-state degeneracy that sustain a large alpha with Cr-mediated control of carrier concentration and a reduced polaron hopping barrier of 0.19eV. This composition achieves a power factor of 40--43 μW/(m K^2) and a zT∼0.072 at 1100K, approximately 2.7 times that of its equimolar analogue. These results demonstrate that targeted cation chemistry and mass contrast, rather than configurational-entropy maximization alone, provide an effective strategy for balancing electronic and phonon transport in multicomponent oxide TE.
ER -