Work

Thermoelectric Properties of Ba8Al16Si30-Based Clathrate Prepared by Combining Arc Melting and Spark Plasma Sintering Methods

Year: 2012

Type: article

Abstract: We investigated the thermoelectric properties of Ba8Al16Si30 clathrate samples prepared by combining arc melting and spark plasma sintering methods under two different arc melting conditions. The x-ray diffraction, scanning electron microscopy, and energy dispersive analysis of x-ray studies indicate that Al composition is close to 15, which is higher than that of a single crystal reported, for both arc melting conditions. The carrier concentration of samples decreases to about 1×1021 cm-3, which is lower than reported values so far in Ba8Al16Si30 system. The Seebeck coefficient and the electrical conductivity alter slightly with the arc melting condition due to the slight difference in the carrier concentration. The lattice thermal conductivity (RT) is as low as about 1.3 Wm-1K-1, which is comparable to Bi2Te3-based bulk alloy, independently of the arc melting condition. The thermoelectric figure of merit ZT is about 0.4 at 900 K. An estimation indicates that ZT reaches 0.8 (1200 K) at the optimum carrier concentration of about 3×1020 cm-3 in Ba8Al16Si30 system.

Source: Journal of the Japan Society of Powder and Powder Metallurgy

DOI: 10.2497/jjspm.59.185

Authors: Hiroaki Anno, Ritsuko Shirataki, Masahiro Hokazono

Institutions: Japan Science and Technology Agency, Sanyo-Onoda City University

Language: English

Topic: Advanced Thermoelectric Materials and Devices

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: diamond

Funder: Japan Society for the Promotion of Science

Award: Study on control of guest-host interactions and thermoelectric properties in clathrate semiconductors