title: Thermoelectric Properties of As-Based Zintl Compounds Ba1-xKxZn2As2.
abstract: As-based Zintl compounds Ba1-xKxZn2As2were prepared by solid-state reaction followed by hot pressing. Ba1-xKxZn2As2(x ≤ 0.02) crystallizes in the α-BaCu2S2-type structure (space group Pnma) upon cooling from 900 °C, whereas it crystallizes in the ThCr2Si2-type structure (space group I4/mmm) for x ≥ 0.04. The lattice thermal conductivities are almost equivalent for both crystal structures with relatively low values of 0.8-1.1 W/mK at 773 K. The values are comparable to those of Sb-based Zintl compounds, though Ba1-xKxZn2As2consists of As atoms, which are lighter than Sb atoms. The electrical resistivity and Seebeck coefficient decreases with increasing x, indicating successful hole doping by K substitution. The dimensionless figure-of-merit ZT is 0.67 at 900 K for x = 0.02, opening a new class of thermoelectric materials with the As-based 122 Zintl compounds.
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Kunihiro
authors.identifier: http://orcid.org/0000-0003-3065-4147
authors.initials: K
authors.lastname: Kihou
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Nishiate
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Yamamoto
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST) , Tsukuba, Ibaraki 305-8568, Japan.
authors.forename: Chul-Ho
authors.initials: CH
authors.lastname: Lee