Copper delocalization leads to ultralow thermal conductivity in chalcohalide CuBiSeCl2

Abstract

Mixed anion halide-chalcogenide materials have attracted considerable attention due to their exceptional optoelectronic properties, making them promising candidates for various applications. Among these, CuBiSeCl_2 has recently been experimentally identified with remarkably low lattice thermal conductivity (k_L). In this study, we employ Wigner transport theory combined with neuroevolution machine learning potential (NEP)-assisted self-consistent phonon calculations to unravel the microscopic origins of this low k_L. Our findings reveal that the delocalization and weak bonding of copper atoms are key contributors to the strong phonon anharmonicity and wavelike tunneling (random walk diffusons). These insights deepen our understanding of the relationship between bonding characteristics, anharmonicity, delocalization, and vibrational dynamics, paving the way for the design and optimization of CuBiSeCl_2 and analogous materials for advanced phonon engineering applications.

References in corpus (10)

• GPUMD: A package for constructing accurate machine-learned potentials and performing highly efficient atomistic simulations
• Accelerating first-principles estimation of thermal conductivity by machine-learning interatomic potentials: A MTP/ShengBTE solution
• Microscopic Mechanisms of Glass-Like Lattice Thermal Transport in Cubic Cu${}_{12}$Sb${}_4$S${}_{13}$ Tetrahedrites
• Unravelling Ultralow Thermal Conductivity in Double Perovskite Cs2AgBiBr6: Dominant Wave-like Phonon Tunnelling, Strong Quartic Anharmonicity and Lattice Instability
• Molecular dynamics simulations of heat transport using machine-learned potentials: A mini review and tutorial on GPUMD with neuroevolution potentials
• Spectral Decomposition of Thermal Conductivity: Comparing Velocity Decomposition Methods in Homogeneous Molecular Dynamics Simulations
• The role of high-order anharmonicity and off-diagonal terms in thermal conductivity: a case study of multi-phase CsPbBr3
• Machine learning for predicting ultralow thermal conductivity and high ZT in complex thermoelectric materials
• Anomalous thermal conductivity in 2D silica nanocages of immobilizing noble gas atom
• Bonding Hierarchy and Coordination Interaction Leading to High Thermoelectricity in Wide Bandgap TlAgI2

Cited by in corpus (2)

• First-principles study of photovoltaic and thermoelectric properties of AgBiSCl2
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