Abstract
Defect engineering in thermoelectric materials leads to the formation of exotic transport properties. Specifically, reduction in lattice thermal conductivity (кL) can be realized through scattering of low and high-frequency phonons by interfacial and point defects respectively. Herein we explore such phenomena by inducing dense dislocations through doping of rare earth (RE) impurities in β-(Zn1−xREx)4Sb3 [x = 0.3–0.5 at.%] as phonon scattering source of all frequencies. Lattice anharmonicity created results in an ultra-low кL of ~0.15 W/mK for β-(Zn0.997 Yb0.003)4Sb3. Vibrational properties and phonon scattering altered by the lattice anharmonicity are studied in detail through terahertz and infrared spectroscopies.
Original language | English |
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Pages (from-to) | 95-101 |
Number of pages | 7 |
Journal | Scripta Materialia |
Volume | 174 |
DOIs | |
Publication status | Published - 1 Jan 2020 |
Keywords
- Anharmonicity
- Defect engineering
- Impurity-doping
- Lattice dislocations
- Thermal conductivity
- Thermoelectrics
ASJC Scopus subject areas
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys