Plastic strain recovery in nanocrystalline copper thin films

On plastic strain recovery in freestanding nanocrystalline metal thin films

In a recent article [J. Rajagopalan, J.H. Han, M.T.A. Saif, Science 315 (2007) 1831–1834], we have reported substantial (50–100%) plastic strain recovery in freestanding nanocrystalline metal films (grain size 50–65 nm) after unloading. The strain recovery was time dependent and thermally activated. Here we model the time evolution of this strain recovery in terms of a thermally activated dislo...

Plastic deformation recovery in freestanding nanocrystalline aluminum and gold thin films.

In nanocrystalline metals, lack of intragranular dislocation sources leads to plastic deformation mechanisms that substantially differ from those in coarse-grained metals. However, irrespective of grain size, plastic deformation is considered irrecoverable. We show experimentally that plastically deformed nanocrystalline aluminum and gold films with grain sizes of 65 nanometers and 50 nanometer...

Ferromagnetism in nanocrystalline epitaxial Co:TiO2 thin films

In situ TEM study of grain growth in nanocrystalline copper thin films.

Nanocrystalline metals demonstrate a range of fascinating properties, including high levels of mechanical strength. However, as these materials are exposed to high temperatures, it is critical to determine the grain size evolution, as this process can drastically change the mechanical properties. In this work, nanocrystalline sputtered Cu thin films with 43 +/- 2 nm grain size were produced by ...

Nanocrystalline silicon thin films on PEN substrates

We study the structural and electrical properties of intrinsic layers growth close to the transition between amorphous silicon (a-Si:H) and nanocrystalline silicon (nc-Si:H) deposited on glass and PEN without intentional heating. These samples showed different behaviour in Raman shift and XRD spectra when compared with that of samples deposited at 200oC. Electrical properties of these films als...