First‐principles calculations to investigate electronic thermodynamic and optical properties of the RbScO₂ alloy

Vietnam Journal of Chemistry, Journal Year: 2024, Volume and Issue: unknown

Published: Aug. 27, 2024

Abstract In this study, we explore the electronic, thermodynamic, and optical properties of compound RbScO₂ using density functional theory (DFT) incorporating a U‐correction term, known as Hubbard correlation energy. This approach enables us to gain an in‐depth understanding band structure, states, specific RbScO₂. The results reveal that exhibits indirect gap measuring 3.68 eV for GGA+SOC+U. Importantly, is located at Γ‐VBM M‐CBM points Brillouin zone. were studied in xx , yy zz directions, revealing significant increase absorption coefficient with higher photon energies, including distinct peak UV range. Increased was observed along axes under pressure 50 GPa. Additionally, thermodynamic attributes RbScO₂, volume, Debye temperature, heat capacity, entropy, examined. It temperature increases proportionately tensile strain but decreases increasing suggesting expansion may compound's mechanical thermal stability. study provides valuable information on characteristics RbScO 2 enriching our its potential applications.

Language: Английский

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Medium-Range Structural Order as the Driver of Activated Dynamics and Complexity Reduction in Glass-Forming Liquids

The Journal of Physical Chemistry B, Journal Year: 2024, Volume and Issue: 128(45), P. 11293 - 11312

Published: Oct. 31, 2024

We analyze in depth the Elastically Collective Nonlinear Langevin Equation theory of activated dynamics metastable liquids to establish that predicted inter-relationships between alpha relaxation time, local cage and collective elastic barriers, dynamic localization length, shear modulus are causally related within medium range order (MRO) static correlation length. The latter grows exponentially with density for hard sphere fluids as a nonuniversal inverse power law temperature supercooled under isobaric conditions. physical origin connections time other metrics thermodynamic dimensionless compressibility is fully established. It discovered although kinetic constraints from real space first coordination shell important they secondary importance compared consequences more universal MRO correlations both modestly deeply regimes. This understanding sheds new light on theoretical basis for, prior successes of, predictive mapping chemically complex thermal effective based matching their compressibilities, scheme we call "complexity reduction". In essence, equivalent requirement liquid equals its analog. alone shown provide remarkable level quantitative glass transition Tg 21 molecular polymer liquids. Predictions specific absolute magnitude growth cooling length obtained lie window 2–6 nm at Tg. Dynamic heterogeneity, facilitation, beyond pair structure issues briefly discussed. Future opportunities theoretically equilibrated deep regime outlined.

Language: Английский

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Transport of penetrants in polymeric materials

Polymer International, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 9, 2024

Abstract Transport phenomena of chemical species in polymers underpin many applications. This mini‐review discusses several key transport scenarios polymer gels, melts and crosslinked networks. mechanisms a wide variety penetrant chemistries are discussed via activated hopping theory cover across the rubbery, intermediate/deeply supercooled glassy states polymers. Moreover, we also discuss ionic conductivity electrolytes, emphasizing relationship between ion diffusion segmental relaxation highlighting current challenges community. Finally, potential research directions suggested concerning how external fields, such as mechanical force active matter self‐propelling particles, affect particle offers general overview motivations for studying transports diverse involved. © 2024 Society Chemical Industry.

Language: Английский

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