Resputtering and morphological changes of Au nanoparticles in nanocomposites as a function of the deposition conditions of the oxide capping layer

Abstract

A multilayer nanocomposite consisting of Au nanoparticles separated by layers of amorphous Al2O3 was prepared by pulsed laser deposition. The laser energy density used to deposit the Al2O3 layers was varied to investigate the effects on the resulting microstructure. When Al2O3 is deposited on the Au it results in resputtering and interfacial mixing of the Au nanoparticles into the Al2O3 matrix being deposited onto them. This leads to a reshaping of the nanoparticles, elongating them in the growth direction and in some cases forming cavities in the nanoparticles. These effects become more pronounced with increasing laser energy density. The high kinetic energies of the species involved also result in implantation of Au into the Al2O3 where it forms nanoparticles of about 1 nm mean diameter.

The role of the laser fluence on the Al2O3 target in the nanostructure and morphology of VOx:Al2O3 thin films prepared by pulsed laser deposition

“…This decrease is about 10% and could be related to a small sputtering yield of V during the deposition of Al 2 O 3 . This effect has been observed for nanocomposite Cu:Al 2 O 3 [10] and Au:Al 2 O 3 [11] films. The decrease is especially strong for the Au:Al 2 O 3 nanocomposite films for which fluences similar to that of the V3F film were used.…”

“…The decrease is especially strong for the Au:Al 2 O 3 nanocomposite films for which fluences similar to that of the V3F film were used. A decrease of nearly 50% in the deposited Au with respect to a film that was not covered with Al 2 O 3 was observed [11]. Nevertheless it should be noted that for the V nanocomposite films this effect seems much more limited, most probably because of the reactive nature of V compared to the noble metals.…”

Coverage induced regulation of Au nanoparticles during pulsed laser deposition

“…It has been reported that the competition between surface growth and sputtering at high fluences leads to self-regulation of the dimensions of embedded NPs that narrows the size distributions, 13 and when using high fluences to ablate the Al 2 O 3 host, it leads to a reshaping of the and even to an elongation in the growth direction. 15 It is, in addition, suggested that sputtering by the host depends on the size of the NPs.…”

Si nanoparticle–Er3+ coupling through contact in as-deposited nanostructured films

“…The laser energy density on the targets was below 2 J cm −2 to avoid mixing and resputtering effects. 12 Further details can be found elsewhere. 9,13 The Si NP-Er 3+ doping layers are produced by depositing the two dopants independently and sequentially from pure Si and Er targets.…”