Development of a aggregation source for metallic nano-clusters / Desenvolvimento de uma fonte de nano-agregados metalicos

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Nanosystems are one of the most important fields of research in the current days, mainly motivated by their technological potential. This size regime present new and unexpected properties that strongly differ from their macroscopic counter-part. This happen mainly due to effects arising from their high surface-to-bulk ratio and because their sizes are comparable to the conduction electron wavelength. In particular, one of these systems of great interest is the atom clusters, nano-systems with 2 to 10 7 atoms, where properties vary strongly with particle size and shape. In this way, we have started to develop and construct a source to produce clusters with a controllable number of atoms ranging from 2 up to 100 atoms. A usual clusters source is constituted essentially of an atom source and aggregation chamber, to generate the particles; electrostatic lenses, to guide them; and a mass analyzer, which can also select the particles by mass. For the atom source we have designed two sputtering-like sources, a home-made one inch typical planar magnetron and also a home-made cylindrical one, for axial erosion of wire targets. The aggregation chamber will have a variable length ( » 30 - 100 mm), so we can control the average size of the clusters. A skimmer, two Einzel lenses and a Bessel-Box will be used to guide charged cluster through the instrument. As mass spectrometer we are going to use a home-made Time-Of-Flight (TOF). It is important to say that we choose to build almost all the components at Unicamp, these components will be described in the body of this dissertation. For further studies, the plan is to size select the clusters with an electrical quadrupole and deposit the clusters in a matrix (co-deposition), to be able to transport the samples to study their properties ex situ

ASSUNTO(S)

metallic clusters nanoparticulas nanoestrutura agregados metalicos nanoparticles nanostructures

Documentos Relacionados