Here, a novel synthesis for near monodisperse, sub‐10 nm Bi2Te3 nanoparticles is reported. A new reduction route to bismuth nanoparticles is described, which are then applied as starting materials in the formation of rhombohedral Bi2Te3 nanoparticles. After ligand removal by a novel hydrazine hydrate etching procedure, the nanoparticle powder is spark plasma sintered to a pellet with preserved crystal grain sizes. Unlike previous works on the properties of Bi2Te3 nanoparticles, the full thermoelectric characterization of such sintered pellets shows a highly reduced thermal conductivity and the same electric conductivity as bulk n‐type Bi2Te3.

The synthesis and single crystal growth of clathrate-II Na(24)Si(136) is performed in one step applying the spark plasma treatment to the precursor Na(4)Si(4). The reported results demonstrate a new route to intermetallic compounds facilitated by the electric field and current. SPS is revealed to offer significant opportunities as a novel preparatory method for synthesis and crystal growth of solid state materials.

The high-pressure behavior of the hard material ε-Fe 3 N 1+x was studied up to 33 GPa with in situ X-ray diffraction experiments using diamond anvil cells in combination with synchrotron radiation as well as by ex situ high-temperature, high-pressure treatment at 1600(200) K in a two-stage multianvil device with a Walker-type module. Evaluation of the pressure-volume data up to 10 GPa by fitting a Murnaghan-type equation reveals a bulk modulus of B 0 ) 172( 4) GPa (B′ ) 5.7, fixed). The calculated bulk modulus (220 GPa) on the basis of density-functional theory (GGA-PAW-PBE) is in satisfying agreement with the experimental one. Single crystals of ε-Fe 3 N 1+x as obtained by ex situ high-temperature, high-pressure experiments reveal in X-ray diffraction data refinements a structural model of iron atoms in the motif of a hexagonal close packing with occupation of octahedral voids by nitrogen atoms exhibiting long-range order. The preferred structural model is described in space group P312 (a ) 4.7241(2) Å, c ) 4.3862(2) Å, V ) 84.773(6) Å 3 , Z ) 2, R(F) ) 0.0339, wR(F 2 ) ) 0.0556) and compared to a second model in P6 3 22. This choice of structural description is corroborated by the results of density-functional calculations. These yield a total energy at 0 K, which is 5 kJ/mol lower for the model in space group P312 compared to the second best alternative arrangement. Using micro-and nanoindentation techniques, a Vickers hardness of H V ) 7.4(10) GPa, a nanoindentation hardness of H ) 10.1(8) GPa, as well as a reduced elastic modulus in the amount of E r ) 178(11) GPa were measured for ε-Fe 3 N 1+x single crystals.