Interlaced crystals having a perfect Bravais lattice and complex chemical order revealed by real-space crystallography.
The search for optimal thermoelectric materials aims for structures in which the crystalline order is disrupted to lower the thermal conductivity without degradation of the electron conductivity. Here we report the synthesis and characterisation of ternary nanoparticles (two cations and one anion) that exhibit a new form of crystalline order: an uninterrupted, perfect, global Bravais lattice, in which the two cations exhibit a wide array of distinct ordering patterns within the cation sublattice, forming interlaced domains and phases. Partitioning into domains and phases is not unique; the corresponding boundaries have no structural defects or strain and entail no energy cost. We call this form of crystalline order 'interlaced crystals' and present the example of hexagonal CuInS2. Interlacing is possible in multi-cation tetrahedrally bonded compound with an average of two electrons per bond. Interlacing has minimal effect on electronic properties, but should strongly reduce phonon transport, making interlaced crystals attractive for thermoelectric applications.
Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
Xiao
X
Shen
1] Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA [2] Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA.
Emil A
EA
Hernández-Pagan
Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Wu
W
Zhou
Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA.
Yevgeniy S
YS
Puzyrev
Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA.
Juan-Carlos
JC
Idrobo
1] Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA [2] Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA.
Janet E
JE
Macdonald
Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996, USA.
Stephen J
SJ
Pennycook
1] Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235, USA [2] Vanderbilt Institute for Nanoscale Science and Engineering, Vanderbilt University, Nashville, Tennessee 37235, USA [3] Materials Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA [4] Department of Electrical Engineering and Computer Science, Vanderbilt University, Nashville, Tennessee 37235, USA.
Sokrates T
ST
Pantelides