%0 Journal Article
%A Rodrigues, João Elias F. S.
%A Gainza, Javier
%A Serrano Sanchez, Federico
%A Lopez, Carlos
%A Dura, Oscar J.
%A Nemes, Norbert Marcel
%A Martinez, Jose L.
%A Huttel, Yves
%A Fauth, Francois
%A Fernandez Diaz, Maria Teresa
%A Biskup Zaja, Nevenko
%A Alonso, José Antonio 
%T Structural features, anisotropic thermal expansion, and thermoelectric performance in bulk black phosphorus synthesized under high pressure
%D 2020
%@ 0020-1669
%U https://hdl.handle.net/20.500.14352/104697
%X Black phosphorus (BP) allotrope has an orthorhombic crystal structure with a narrow bandgap of 0.35 eV. This material is promising for 2D technology since it can be exfoliated down to one single layer: the well-known phosphorene. In this work, bulk BP was synthesized under high-pressure conditions at high temperatures. A detailed structural investigation using neutron and synchrotron X-ray diffraction revealed the occurrence of anisotropic strain effects on the BP lattice; the combination of both sets of diffraction data allowed visualization of the lone electron pair 3s(2). Temperature-dependent neutron diffraction data collected at low temperature showed that the a axis (zigzag) exhibits a quasi-temperature-independent thermal expansion in the temperature interval from 20 up to 150 K. These results may be a key to address the anomalous behavior in electrical resistivity near 150 K. Thermoelectric properties were also provided; low thermal conductivity from 14 down to 6 Wm(-1) K-1 in the range 323-673 K was recorded in our polycrystalline BP, which is below the reported values for single-crystals in literature.
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