X-ray diffraction studies of the structure of nanometer-sized crystalline materials

Phonon density of states of nanocrystalline Fe prepared by high-energy ball milling

“…2 A high density of grain boundaries is certainly a distinguishing feature of nanocrystalline materials, but there were also reports that nanocrystalline grainboundary structures are more disordered than grain boundaries in large-grained materials. 3 Although some of these early claims of disorder have been shown to be overstated, 4,5 in the present work we show evidence of nanocrystalline vibrations that involve the motion of stiff crystallites separated by weak intercrystallite forces consistent with disordered grain boundaries.…”

The complete Raman spectrum of nanometric SnO2 particles

“…In this way, one can calculate an average thickness for the shell, dϷ1.1 nm, i.e., approximately two to three unit cells of SnO 2 , which is in agreement with the usual thickness found for surface layers. 23,24 It has been shown that, in the extreme case of single SnO 2 crystals, surface reconstruction in the ͑110͒ surface involves up to three monolayers of atoms and the presence of oxygen vacancies. 25 This gives rise to a nonstoichiometric SnO x at the surface and this could be responsible for producing bands S1 and S2.…”

Atomistic Simulation of Nanocrystalline Materials

“…[l,2] At issue is the question as to whether a novel, "frozen-gas" like state of matter exists in polycrystalline materials with a grain size typically below 10 nm or whether the structure and properties of NCMs can be extrapolated from those of coarse-grained polycrystals. [3,4] In spite of much experimental work attempting to address this issue, a structural model consistent with the observations and one that permits some of the anomalous properties of these materials to be predicted, has not evolved. Our goal has been to develop a molecular-dynamics simulation method to grow space-filling, fully dense three-dimensional polycrystals.…”