Article
Chemistry, Multidisciplinary
C. Y. Wu, X. L. Li, J. C. Han, H. R. Gong, S. F. Zhou
Summary: Combining first-principles calculations and Boltzmann transport theory, this study comparatively investigated the thermoelectric properties of square/octagon (s/o)-bismuth monolayer. The results show that s/o-bismuth monolayer exhibits better thermoelectric properties compared to beta-bismuth monolayer due to lower lattice thermal conductivity and weakened electron-phonon coupling. Phonon frequency and group velocity are found to play important roles in determining the lattice thermal conductivity of s/o-bismuth monolayer, while the Seebeck coefficient and figure of merit are higher than those of beta-bismuth monolayer.
Article
Biochemistry & Molecular Biology
Bindu Rani, Aadil Fayaz Wani, Utkir Bahodirovich Sharopov, Lokanath Patra, Jaspal Singh, Atif Mossad Ali, A. F. Abd El-Rehim, Shakeel Ahmad Khandy, Shobhna Dhiman, Kulwinder Kaur
Summary: This study discusses the thermoelectric properties of PdXSn (X = Zr, Hf) half Heusler materials and investigates the lattice thermal conductivity using effective mass and deformation potential theory. The results indicate that both alloys are stable indirect band gap semiconductors, and their electrical/thermal conductivity is inversely proportional to the effective mass of electrons/holes.
Article
Materials Science, Multidisciplinary
X. Yang, A. Jena, F. Meng, S. Wen, J. Ma, X. Li, W. Li
Summary: In this study, the effect of electron-phonon interaction on the lattice thermal conductivity of graphene was investigated using first-principles calculations. It was found that the indirect coupling between flexural acoustic phonons and electrons has a significant impact on thermal conductivity in graphene, particularly due to the dominance of normal processes. Additionally, an unusual minimum thermal conductivity was observed at a specific charge carrier density in graphene.
MATERIALS TODAY PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Guoqing Sun, Yanhua Cheng, Jinlong Ma, Dongwei Xu, Xiaobing Luo
Summary: The surface hydrogenation of two-dimensional GaN has attracted extensive attention for its potential in electronic devices. This study investigates the strain-dependent thermal transport properties of hydrogenated monolayer GaN. The results show that the thermal conductivity of H-GaN first increases and then decreases with increasing strain, exhibiting a volcanic shape trend. Detailed analyses reveal that the change in phonon lifetime is the primary factor affecting this trend. Furthermore, the study demonstrates that strain combined with nanostructure engineering can effectively regulate the thermal transport properties.
Article
Chemistry, Multidisciplinary
Ke Wang, WuXing Zhou, Yuan Cheng, Min Zhang, Hai Wang, Gang Zhang
Summary: The study investigated how spin affects the phononic properties of CrI3 monolayers, finding that infrared spectra can be used to identify magnetic order and explaining the mechanisms behind thermal expansion coefficients and lattice thermal conductivity being influenced by magnetic phases. This research provides insights into spin-lattice coupling and highlights the potential of spintronic monolayers as thermal switching devices for active heat flow control.
Article
Chemistry, Physical
Asad Ali, Young-Han Shin
Summary: In this study, we utilized USPEX and VASP to discover three new structures of 2D GexSy compounds, and analyzed their electronic structures and thermal conductivity properties.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Kaike Yang, Huai Yang, Yujia Sun, Zhongming Wei, Jun Zhang, Ping-Heng Tan, Jun-Wei Luo, Shu-Shen Li, Su-Huai Wei, Hui-Xiong Deng
Summary: Copper-based materials exhibit unusual properties such as superconductivity, ultralow thermal conductivity, and superionicity. This study demonstrates that the high-lying occupied 3d orbital of copper plays a significant role in causing strong phonon anharmonicity and coupling with its unoccupied 4s state when local symmetry is reduced. The understanding of this phenomenon can explain the reduced lattice thermal conductivity and other unusual physical properties observed in copper compounds.
SCIENCE CHINA-PHYSICS MECHANICS & ASTRONOMY
(2023)
Article
Materials Science, Multidisciplinary
Edi Suprayoga, Witha B. K. Putri, Kunchit Singsoog, Supasit Paengson, Muhammad Y. Hanna, Ahmad R. T. Nugraha, Dicky R. Munazat, Budhy Kurniawan, Muhammad Nurhuda, Tosawat Seetawan, Eddwi H. Hasdeo
Summary: The study shows that Bi doping can improve the electron and phonon transport properties of CaMnO3, restoring its behavior to that of ordinary metals. Bi doping also significantly enhances the thermoelectric performance of the material.
MATERIALS RESEARCH BULLETIN
(2021)
Article
Chemistry, Physical
Bin Yang, Shuangming Li, Xin Li, Zhenpeng Liu, Dou Li, Hong Zhong, Songke Feng
Summary: Through theoretical calculations, the lattice thermal conductivity contributions of SnTe were synthesized, with acoustic modes identified as the major contributor. Additionally, designing nanostructures with characteristic lengths less than 14.5nm proved to be an effective method for reducing thermal conductivity.
Article
Chemistry, Multidisciplinary
Shakeel Ahmad Khandy, Jeng-Da Chai
Summary: This study explores the origin of the semimetallic pseudo gap and the role of site preference in the L(2)1-type Heusler compound Ru2TaGa. Detailed analyses of the structural stability, phonon-dependent properties, electronic structure, and thermoelectric properties are presented, revealing the formation mechanism of a pseudo gap and the enhanced thermoelectric performance in Ru2TaGa compared to other compounds in the same family.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2021)
Article
Chemistry, Multidisciplinary
Fei Jia, Shuang Zhao, Jing Wu, Ling Chen, Te-Huan Liu, Li-Ming Wu
Summary: This study reports a unique ternary sulfide compound, Cu3BiS3, with ultralow thermal conductivity. By using DFT calculations and analysis, researchers found that the Cu atoms in Cu3BiS3 are coordinated in a two-dimensional triangular arrangement, leading to efficient out-of-plane phonon scattering and reduced thermal conductivity.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Physics, Applied
Zongwei Zhang, Honghao Yao, Xue Jia, Xinyu Wang, Xiaofang Li, Chen Chen, Xi Lin, Jiehe Sui, Xingjun Liu, Jun Mao, Guoqiang Xie, Qian Zhang
Summary: The study demonstrates that alignment of valence bands through alloying and doping can enhance the thermoelectric performance of zintl phases, with increased Seebeck coefficient and decreased lattice thermal conductivity achieved in CaCd2Sb2 through manipulation of valence band degeneracy.
APPLIED PHYSICS LETTERS
(2022)
Article
Nanoscience & Nanotechnology
Qing Zhou, Xiaojian Tan, Qiang Zhang, Ruoyu Wang, Zhe Guo, Jianfeng Cai, Jun Ye, Guoqiang Liu, Jun Jiang
Summary: This study reports the synergistic optimization of the thermoelectric properties of p-type GeTe through Bi-Cu2S coalloying. The donor behavior of Bi and the substitution-interstitial defect pairs of Cu+ ions effectively reduce the hole concentration without significantly affecting the carrier mobility. The coalloying also induces many phonon scattering centers and suppresses the lattice thermal conductivity, resulting in a high ZT and theoretical conversion efficiency.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Nanoscience & Nanotechnology
Mengrong Li, Pengzhan Ying, Zhengliang Du, Xianglian Liu, Xie Li, Teng Fang, Jiaolin Cui
Summary: By alloying with Ag0.5Bi0.5Se and ZnO sequentially, both the electronic and phonon transports of SnTe were engineered to increase the Seebeck coefficient and reduce thermal conductivity. This synergistic engineering led to a significant improvement in TE performance with a peak ZT value of about 1.2 at around 870 K for the sample.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Xiong Yang, Yanxia Wang, Ruonan Min, Zongning Chen, Enyu Guo, Huijun Kang, Linwei Li, Xue Jiang, Tongmin Wang
Summary: In this study, the thermal and electrical conductivities of ZrNiSnbased alloys were synergistically optimized by Ta doping and Hf substitution. The introduction of Ta and Hf resulted in increased electrical conductivity and reduced lattice thermal conductivity, leading to a significantly enhanced thermoelectric performance.
Article
Chemistry, Medicinal
Hadrian Montes-Campos, Jesus Carrete, Sebastian Bichelmaier, Luis M. Varela, Georg K. H. Madsen
Summary: NEURALIL is an effective model for predicting the potential energy of ionic liquids, achieving accurate results with significant savings in computational cost by training on ab initio forces. By utilizing appropriate descriptor encoding and force information, higher accuracy is achieved, reducing the amount of data required for training.
JOURNAL OF CHEMICAL INFORMATION AND MODELING
(2022)
Article
Physics, Condensed Matter
Lijun Pan, Jesus Carrete, Zhao Wang
Summary: In this study, the effect of biaxial tensile strain on phonon transport in a Janus PtSTe monolayer was investigated using first-principles calculations and Boltzmann transport theory. It was found that the lattice thermal conductivity decreases nonlinearly with increasing strain, reaching close to an order of magnitude reduction when the band gap disappears completely under high strains (>8%). This behavior is attributed to a strong enhancement of anharmonic scattering of acoustic phonons due to the band overlap.
JOURNAL OF PHYSICS-CONDENSED MATTER
(2022)
Article
Materials Science, Multidisciplinary
Sebastian Bichelmaier, Jesus Carrete, Michael Nelhiebel, Georg K. H. Madsen
Summary: A method based on effective harmonic potentials is proposed to study the potential energy surface of anharmonic materials, and an introduction of reweighting procedure enables the usage of unregularized regression. The method is tested on the high-temperature cubic phase of HfO2 and the calculated temperature-dependent physical properties are in agreement with existing experimental data, suggesting the potential for predictive treatment of HfO2 over a wide temperature range.
PHYSICA STATUS SOLIDI-RAPID RESEARCH LETTERS
(2022)
Article
Chemistry, Physical
Peter Kovacs, Fabien Tran, Peter Blaha, Georg K. H. Madsen
Summary: This study systematically explores the space of generalized gradient approximation (GGA) and meta-GGA (mGGA) exchange approximations by training new functionals, aiming to improve accurate predictions of lattice parameter, cohesive energy, and bandgap. The trained functionals perform similarly to specialized functionals for bandgap predictions and outperform them for the other two properties.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Materials Science, Multidisciplinary
Lijun Pan, Zhao Wang, Jesus Carrete, Georg K. H. Madsen
Summary: Ab initio calculations were used to study the phonon and charge-carrier transport in the Janus PtSTe monolayer. The results showed a significant improvement in the thermoelectric performance, mainly due to the reduction in thermal conductivity resulting from the relaxation of selection rules for three-phonon scattering. This suggests that Janus monolayers have great potential for thermoelectric applications among quasi-two-dimensional systems.
PHYSICAL REVIEW MATERIALS
(2022)
Article
Computer Science, Interdisciplinary Applications
Marti Raya-Moreno, Xavier Cartoixa, Jesus Carrete
Summary: We introduce BTE-Barna, a software package that extends the MC module of the almaBTE solver for phonon transport in nanosystems based on 2D materials. It incorporates the propagator for the full linearized version of the PBTE, allowing accurate modeling of scattering-induced phonon occupation evolution in momentum space. The code can find solutions for finite and extended devices with thermal gradients, isothermal reservoirs, or arbitrary initial temperature distributions, providing temperature and heat flux distributions as well as their spectral decompositions.
COMPUTER PHYSICS COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Sebastian Bichelmaier, Jesus Carrete, Georg K. H. Madsen
Summary: Given the high cost of ab-initio calculations, it is challenging to predict temperature-dependent phenomena in strongly anharmonic systems. A possible solution is to use a relatively inexpensive surrogate model for the potential energy surface to build temperature-dependent effective harmonic potentials. However, the results may only be valid in a narrow temperature range due to the limited flexibility of polynomials as approximants, leading to significant artifacts in derived quantities. A global interpolation strategy, such as a neural-network force field, is suggested as a better approach to cost-effective surrogate models.
INTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY
(2023)
Article
Chemistry, Physical
Jesus Carrete, Hadrian Montes-Campos, Ralf Wanzenboeck, Esther Heid, Georg K. H. Madsen
Summary: A reliable uncertainty estimator is crucial for using machine-learning force fields effectively. This study proposes a generalized deep-ensemble design using multiheaded neural networks and a heteroscedastic loss to handle uncertainties in energy and forces and consider aleatoric uncertainty sources in training data. Uncertainty metrics are compared for deep ensembles, committees, and bootstrap-aggregation ensembles using data for an ionic liquid and a perovskite surface. An adversarial approach to active learning is demonstrated for progressively refining force fields, made possible by fast training with residual learning and a nonlinear learned optimizer.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Raveena Gupta, Sonali Kakkar, Bonny Dongre, Jesus Carrete, Chandan Bera
Summary: Nanostructuring is a well-known method to improve the thermoelectric figure of merit, but it has limitations in tuning the lattice thermal conductivity. The thermoelectric properties of the SnS monolayer are investigated under uniaxial compressive and tensile strains using first-principles calculations and the Boltzmann transport equation. It is found that applying uniaxial compressible and tensile strains along the armchair direction can significantly enhance the power factor and figure of merit of the material, making it a promising candidate for thermoelectric applications.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Maximilian Wolf, Georg K. H. Madsen, Theodoros Dimopoulos
Summary: Researchers have developed a high-throughput platform for the deposition and analysis of combinatorial thin films of copper-gallium-iron oxides. The platform allows for fast and accurate screening of the films' chemical composition, crystallographic structure, thickness, and optical properties. This work offers an efficient method for overcoming the time and labor-intensive nature of conventional material research.
MATERIALS ADVANCES
(2023)
Article
Materials Science, Multidisciplinary
Sebastian Bichelmaier, Jesus Carrete, Ralf Wanzenboeck, Florian Buchner, Georg K. H. Madsen
Summary: This study explores the complex phase structure of HfO2 using effective harmonic potentials based on a neural-network force field (NNFF), providing almost ab-initio accuracy at a reduced cost. The results show that the thermal expansion coefficient of low-symmetry phases agrees with experimental results, and the P4 over bar 3m phase is identified as the favorable cubic phase. However, the experimental lattice constants of the cubic phases are larger than the calculated values for the corresponding stoichiometric phases. Furthermore, the stoichiometric cubic phases are unlikely to be thermodynamically stable compared to other phases.
Article
Chemistry, Multidisciplinary
Esther Heid, Daniel Probst, William H. Green, Georg K. H. Madsen
Summary: Enzymatic reactions are ecofriendly and versatile for chemical synthesis. Computational models are important for predicting enzymatic activity and reaction outcomes. However, limited data and the presence of machine learning components pose challenges to current approaches.
Article
Materials Science, Multidisciplinary
Guijian Pang, Bo Zhang, Fanchen Meng, Zhe Liu, Yani Chen, Wu Li
Summary: In this study, we calculated the lattice and electronic thermal conductivity of arsenic using first-principles methods and found significant anisotropy in the lattice thermal conductivity. The electronic thermal conductivity was almost isotropic. Strong anharmonic interatomic interactions in arsenic limited the enhancement of lattice thermal conductivity. Compared to neighboring germanium, arsenic exhibited stronger anharmonic interactions but minimal effects of phonon-electron interactions on the lattice thermal conductivity at room temperature.