TY - JOUR
T1 - Intricate Short-Range Ordering and Strongly Anisotropic Transport Properties of Li1-xSn2+xAs2
AU - Lee, Kathleen
AU - Kaseman, Derrick
AU - Sen, Sabyasachi
AU - Hung, Ivan
AU - Gan, Zhehong
AU - Gerke, Birgit
AU - Pöttgen, Rainer
AU - Feygenson, Mikhail
AU - Neuefeind, Jörg
AU - Lebedev, Oleg I.
AU - Kovnir, Kirill
N1 - Publisher Copyright:
© 2015 American Chemical Society.
PY - 2015/3/18
Y1 - 2015/3/18
N2 - A new ternary compound, Li1-xSn2+xAs2, 0.2 < x < 0.4, was synthesized via solid-state reaction of elements. The compound crystallizes in a layered structure in the R3¯m space group (No. 166) with Sn-As layers separated by layers of jointly occupied Li/Sn atoms. The Sn-As layers are comprised of Sn3As3 puckered hexagons in a chair conformation that share all edges. Li/Sn atoms in the interlayer space are surrounded by a regular As6 octahedron. Thorough investigation by synchrotron X-ray and neutron powder diffraction indicate no long-range Li/Sn ordering. In contrast, the local Li/Sn ordering was revealed by synergistic investigations via solid-state 6,7Li NMR spectroscopy, HRTEM, STEM, and neutron and X-ray pair distribution function analyses. Due to their different chemical natures, Li and Sn atoms tend to segregate into Li-rich and Sn-rich regions, creating substantial inhomogeneity on the nanoscale. The inhomogeneous local structure has a high impact on the physical properties of the synthesized compounds: the local Li/Sn ordering and multiple nanoscale interfaces result in unexpectedly low thermal conductivity and highly anisotropic resistivity in Li1-xSn2+xAs2. (Graph Presented).
AB - A new ternary compound, Li1-xSn2+xAs2, 0.2 < x < 0.4, was synthesized via solid-state reaction of elements. The compound crystallizes in a layered structure in the R3¯m space group (No. 166) with Sn-As layers separated by layers of jointly occupied Li/Sn atoms. The Sn-As layers are comprised of Sn3As3 puckered hexagons in a chair conformation that share all edges. Li/Sn atoms in the interlayer space are surrounded by a regular As6 octahedron. Thorough investigation by synchrotron X-ray and neutron powder diffraction indicate no long-range Li/Sn ordering. In contrast, the local Li/Sn ordering was revealed by synergistic investigations via solid-state 6,7Li NMR spectroscopy, HRTEM, STEM, and neutron and X-ray pair distribution function analyses. Due to their different chemical natures, Li and Sn atoms tend to segregate into Li-rich and Sn-rich regions, creating substantial inhomogeneity on the nanoscale. The inhomogeneous local structure has a high impact on the physical properties of the synthesized compounds: the local Li/Sn ordering and multiple nanoscale interfaces result in unexpectedly low thermal conductivity and highly anisotropic resistivity in Li1-xSn2+xAs2. (Graph Presented).
UR - http://www.scopus.com/inward/record.url?scp=84925273757&partnerID=8YFLogxK
U2 - 10.1021/jacs.5b00237
DO - 10.1021/jacs.5b00237
M3 - Article
AN - SCOPUS:84925273757
SN - 0002-7863
VL - 137
SP - 3622
EP - 3630
JO - Journal of the American Chemical Society
JF - Journal of the American Chemical Society
IS - 10
ER -