An overview of key experimental data and theoretical representations on fracture processes in nanoceramics is presented. The focuses are placed on crack growth in nanoceramics and their toughening micromechanics. Conventional toughening micromechanisms are discussed which effectively operate in both microcrystalline-matrix ceramics containing nanoinclusions and nanocrystalline-matrix ceramics. ...

Resistivity, Seebeck coefficient, and Hall measurements were performed on densified nanocrystalline composite materials of undoped and Ag-doped PbTe nanocrystals to investigate the physical mechanisms responsible for Seebeck coefficient enhancement in nanocrystalline systems. The unique temperature dependence of the resistivity and mobility for these PbTe nanocomposites suggests that grain-boun...

Anode materials of nanostructured silicon have been prepared by physical vapor deposition and characterized using electrochemical methods. The electrodes were prepared in thin-film form as nanocrystalline particles ~12 nm mean diameter! and as continuous amorphous thin films ~100 nm thick!. The nanocrystalline silicon exhibited specific capacities of around 1100 mAh/g with a 50% capacity retent...

Making use of the stress induced magnetic anisotropy in some iron-rich FeCuh'bSiB nanocrystalline materials we studied the thermal dependence of their magnetostriction which becomes zero below the Curie temperature. The choice of a suitable composition and annealing temperature results in materials with zero magnetostriction at room temperature. Due to the low magnetostriction these materials h...

− The article surveys amorphous and nanocrystalline alloys for soft magnetic applications. Both materials have much in common starting from their way of production and ranging over to the key factors which determine their properties. Thus, the magneto-crystalline anisotropy is randomly fluctuating on a scale much smaller than the domain wall width and, as a consequence, is averaged out by excha...

We describe a method to simulate on macroscopic time scales the stress relaxation in an atomistic nanocrystal model under an imposed strain. Using a metadynamics algorithm for transition state pathway sampling we follow the full evolution of a classical anelastic relaxation event, with relaxation times governed by the nanoscale microstructure imperfections in the solid. We show that probing thi...

Density functional theory (DFT) modelling of the alkane-SnO2 surface interaction correctly predicts the results of the chemoresistive alkane sensing tests, provided that the highly reduced nature of the SnO2 nanocrystal surface is properly inserted in the model.

One of the main concerns in the technological application of several metal-organic frameworks (MOFs) relates to their structural instability under pressure (after a conforming step). Here we report for the first time that mechanical instability can be highly improved via nucleation and growth of MOF nanocrystals in the confined nanospace of activated carbons.