Work

Creep behavior and post-creep thermoelectric performance of the n-type Skutterudite alloy Yb0.3Co4Sb12

Year: 2020

Type: article

Abstract: Upon uniaxial compressive loading at 500 °C (T/Tm = 0.67, where Tm is the absolute melting point), the n-type Skutterudite alloy Yb0.3Co4Sb12 deforms plastically by creep via a power-law, with a stress exponent ∼3 consistent with dislocation viscous glide. An activation energy of 171 kJ/mol is measured over the temperature range of 500–587 °C (T/Tm = 0.67–0.75) at a stress of 30 MPa. Yb0.3Co4Sb12 is ductile at 500 °C, exhibiting a compressive strain of 25% when subjected to stresses ranging from 22 to 90 MPa for up to 28 days. Among the thermoelectric materials tested so far for creep, Yb0.3Co4Sb12 exhibits a creep resistance intermediate between low-melting (Bi2Te3, TAGS-85) and high-melting thermoelectrics (Mg2Si and ZrNiSn). A relatively modest drop in the figure of merit zT, from 0.67 to 0.52, is displayed by Yb0.3Co4Sb12 after accumulating 3.7% compressive creep strain at 500 °C, mostly due to a drop in electrical conductivity.

Source: Journal of Materiomics

DOI: 10.1016/j.jmat.2020.07.012

Authors: Muath M. Al Malki, Xun Shi, Pengfei Qiu, G. Jeffrey Snyder, David C. Dunand

Institutions: Northwestern University, King Fahd University of Petroleum and Minerals, Chinese Academy of Sciences, Shanghai Institute of Ceramics, State Key Laboratory of High Performance Ceramics and Superfine Microstructure

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $1,750