%0 Journal Article
%A Gainza, Javier
%A Molto, Sergio
%A Serrano Sánchez, Federico
%A Dura, Óscar 
%A Fernández Díaz, Maria Teresa
%A Biskup Zaja, Nevenko
%A Martínez, Jose Luis
%A Alonso, José Antonio 
%A Nemes, Norbert Marcel
%T SnSe: Kx intermetallic thermoelectric polycrystals prepared by arc-melting
%D 2022
%@ 0022-2461
%U https://hdl.handle.net/20.500.14352/91198
%X Neutron powder diffraction and thermoelectric characterization of SnSe:Kx intermetallic alloys are presented. Nanostructured ingots were prepared by arc-melting elemental tin and selenium along with potassium hydride. Up to x = 0.1 of K can be incorporated into SnSe. Rietveld refinement of the diffractograms locates potassium on the Sn site in the high-temperature Cmcm structure. However, in the low-temperature Pnma structure, K cannot be localized by difference Fourier maps, indicating the incorporation of K in a disordered form in the interlayer space. STEM-EELS indicates the incorporation of K into the SnSe grains. The resistivity upon K-doping at intermediate temperatures decreases by 1–2 orders of magnitude, but at high temperature is higher than the undoped SnSe. The Seebeck coefficient of K-doped SnSe remains p-type and almost temperature independent (400 μV/K for x = 0.1). The ultralow thermal conductivity of undoped SnSe decreases further upon K-doping to below 0.3 W/m K.
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