Significant four-phonon scattering and its heat transfer implications in crystalline Ge${}_2$Sb${}_2$Te${}_5$

Abstract

We systematically demonstrate the temperature-dependent thermal transport properties in crystalline Ge${}_2$Sb${}_2$Te${}_5$via first-principles density functional theory-informed linearized Boltzmann transport equation. The investigation, covering a wide temperature range (30 K-600 K), reports the emergence of an unusual optical phonon-dominated thermal transport in crystalline Ge${}_2$Sb${}_2$Te${}_5$. Further, a significant contribution of four-phonon scattering is recorded which markedly alters the lattice thermal conductivity. Therefore, the combined effect of cubic and quartic phonon anharmonicity is seen to navigate the underlying physical mechanism and open up intriguing phononic interactions in Ge${}_2$Sb${}_2$Te${}_5$ at high temperature. Irrespective of three and four-phonon processes, Umklapp is seen to prevail over normal scattering events. Consequently, four-phonon scattering is found to notably reduce the lattice thermal conductivity of Ge${}_2$Sb${}_2$Te${}_5$ to 28 $\%$ at room temperature and 42 $\%$ at higher temperature. This quartic anharmonicity further manifests in the breakdown of T${}^{-1}$ scaling of thermal conductivity and challenges the idea of a universal lower bound to phononic thermal diffusivity at high temperature. The faster decay of thermal diffusivity compared to T${}^{-1}$ is rationalized encompassing the quartic anharmonicity via a modified time scale. These results invoke better understanding and precision to the theoretical prediction of thermal transport properties of Ge${}_2$Sb${}_2$Te${}_5$. Concomitantly, this also triggers the possibility to explore the manifestations of the lower bound of thermal diffusivity in materials possessing pronounced four-phonon scattering.

References in corpus (18)

• Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Phonons and related properties of extended systems from density-functional perturbation theory
• Theory of universal incoherent metallic transport
• Four-phonon scattering diminishes the optical phonon contribution and isotope effect to thermal conductivity of III-V semiconductors
• Planckian Dissipation in Metals
• Phonon-Phonon Interactions in Strongly Bonded Solids: Selection Rules and Higher-Order Processes
• Anharmonic Phonon Quasiparticle Theory of Zero-point and Thermal Shifts in Insulators: Heat Capacity, Bulk Modulus, and Thermal Expansion
• Electronic, optical and thermal properties of the hexagonal and fcc Ge2Sb2Te5 chalcogenide from first-principle calculations
• The role of high-order anharmonicity and off-diagonal terms in thermal conductivity: a case study of multi-phase CsPbBr3
• Limits of the phonon quasi-particle picture at the cubic-to-tetragonal phase transition in halide perovskites
• Thermal conductivity of amorphous and crystalline GeTe thin film at high temperature: Experimental and theoretical study
• On the Planckian bound for heat diffusion in insulators
• Phonon hydrodynamics in crystalline materials
• A lower bound to the thermal diffusivity of insulators
• Phonon hydrodynamics in crystalline GeTe at low temperature
• Electronic and Thermal Properties of ${\text{GeTe/Sb}}_2{\text{Te}}_3$ Superlattices by ab-initio Approach: Impact of Van der Waals Gaps on Vertical Lattice Thermal Conductivity