Quaternary Zintl Phases Ba2InSnP3 and Ba2InSnAs3 with Complex Structures and n-Type Semiconducting Behavior

Document Type

Article

Publication Date

8-13-2024

Abstract

Presented are the crystal structures and the transport properties of the novel quaternary pnictides with the general formula Ba3InSnPn3 (Pn = P, As). Large single crystals of the phosphide, arsenide, and the P/As solid solution can be readily synthesized by using reactions with molten Sn as a choice of a reactive metal flux. The title compounds crystallize in a monoclinic crystal system with a new structure type. The structure features a 3D polyanionic sublattice of corner- and edge-sharing [M4Pn10] units made of double-corner-sharing ethane-like [M2Pn6] fragments (M = In/Sn). Comprehensive crystallographic studies, including single-crystal neutron diffraction, confirm the random distribution of In and Sn atoms; i.e., there is no long-range ordering. The equiatomic statistical distribution of In and Sn allows for the simultaneous existence of In-In, Sn-Sn, as well as In-Sn bonds, yielding closed-shell electronic configuration in atypical In2+ and Sn3+ states. Partitioning of the valence electrons as (Ba2+)3(In2+)(Sn3+)(Pn3-)3 shows charge-balanced compositions; i.e., the compounds are Zintl phases. The expected valence-precise behavior is corroborated by both electronic structure calculations and electrical resistivity measurements, which show intrinsic narrow band gap semiconductors. Thermal and electrical transport measurements for single-crystalline Ba3InSnAs3 indicate an n-type charge transport mechanism with a relatively low charge-carrier concentration and mobility of electrons as the dominant charge carriers (n300K ≈ 1 × 1017 cm-3, μ300K ≈ 4 cm2/V s).

Publication Source (Journal or Book title)

Chemistry of Materials

First Page

7570

Last Page

7580

This document is currently not available here.

Share

COinS