Reduced thermal conductivity of TiNiSn/HfNiSn superlattices

Article

关键词: ENHANCED THERMOELECTRIC PERFORMANCE;    HALF-HEUSLER COMPOUNDS;    MICROWAVE PREPARATION;    PHASE-SEPARATION;    3-OMEGA METHOD;    TINISN;    TEMPERATURE;    ALLOYS;    REDUCTION;    MERIT;   

DOI  :  10.1103/PhysRevB.92.125436

来源: SCIE

【 摘 要 】

Diminution of the thermal conductivity is a crucial aspect in thermoelectric research. We report a systematic and significant reduction of the cross-plane thermal conductivity in a model system consisting of dc sputtered TiNiSn and HfNiSn half-Heusler superlattices. The reduction of kappa is measured by the 3 omega method and originates from phonon scattering at the internal interfaces. Heat transport in the superlattices is calculated based on Boltzmann transport theory, including a diffusive mismatch model for the phonons at the internal interfaces. Down to a superlattice periodicity of 3 nm the phonon spectrum mismatch between the superlattice components quantitatively explains the reduction of kappa. For very thin individual layers the interface model breaks down and the artificial crystal shows an enhanced kappa.

【 授权许可】

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