s-d Coupling-Induced Dynamic Off-Centering of Cu Drives High Thermoelectric Performance in TlCuS DOI
Animesh Bhui, Matukumilli V. D. Prasad,

Shuva Biswas

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Seeking new and efficient thermoelectric materials requires a detailed comprehension of chemical bonding structure in solids at microscopic levels, which dictates their intriguing physical properties. Herein, we investigate the influence local structural distortion on properties TlCuS, layered metal sulfide featuring edge-shared Cu-S tetrahedra within Cu2S2 layers. While powder X-ray diffraction suggests average crystallographic symmetry with no CuS4 tetrahedra, synchrotron pair distribution function experiment exposes concealed breaking, dynamic off-centering distortions tetrahedra. The Cu is driven by on-site coupling filled 3d unoccupied 4s orbitals (s-d) through second-order Jahn-Teller mechanism. Bond softening p-d* (S-3p Cu-3d) antibonding interaction coupled causes significant anharmonicity lattice, acts as phonon-blocking mechanism conducive to ultralow lattice thermal conductivity (κlat) (∼0.35-0.23 W m-1 K-1 ∼296-573 K temperature range) TlCuS. synergy between low κlat multiband electronic leads figure-of-merits (zT) ∼1 ∼1.3 573 for pristine TlCuS TlCu0.98S, respectively, underscoring potential sulfides promising high-performance thermoelectrics.

Language: Английский

s-d Coupling-Induced Dynamic Off-Centering of Cu Drives High Thermoelectric Performance in TlCuS DOI
Animesh Bhui, Matukumilli V. D. Prasad,

Shuva Biswas

et al.

Journal of the American Chemical Society, Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 14, 2025

Seeking new and efficient thermoelectric materials requires a detailed comprehension of chemical bonding structure in solids at microscopic levels, which dictates their intriguing physical properties. Herein, we investigate the influence local structural distortion on properties TlCuS, layered metal sulfide featuring edge-shared Cu-S tetrahedra within Cu2S2 layers. While powder X-ray diffraction suggests average crystallographic symmetry with no CuS4 tetrahedra, synchrotron pair distribution function experiment exposes concealed breaking, dynamic off-centering distortions tetrahedra. The Cu is driven by on-site coupling filled 3d unoccupied 4s orbitals (s-d) through second-order Jahn-Teller mechanism. Bond softening p-d* (S-3p Cu-3d) antibonding interaction coupled causes significant anharmonicity lattice, acts as phonon-blocking mechanism conducive to ultralow lattice thermal conductivity (κlat) (∼0.35-0.23 W m-1 K-1 ∼296-573 K temperature range) TlCuS. synergy between low κlat multiband electronic leads figure-of-merits (zT) ∼1 ∼1.3 573 for pristine TlCuS TlCu0.98S, respectively, underscoring potential sulfides promising high-performance thermoelectrics.

Language: Английский

Citations

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