Synthesis of nanoparticles in the gas phase for electronic, optical and magnetic applications—a review

https://repository.ubn.ru.nl/bitstream/handle/2066/112848/112848.pdf

Electronic properties of small metallic particles

Granular Metal Films

The appearance of smoke was studied by a video tape recorder. A typical smoke consisted of inner zone, inner front, outer zone and outer front. Smoke particles collected at different parts were studied by electron microscopy. They were large and often showed clear-cut habits in the inner front, while they were small and uniform in the inner and outer zones. The particle size varied with the gas pressure, evaporation temperature and position of collecting particles. The particles grow remarkably by coalescence where no metal vapour exists. All the experimental results on the size can be explained with an empirical rule that particles become larger when the nucleation starts in vapour of higher density.

Formation of Ultrafine Metal Particles by Gas Evaporation Technique. I. Aluminium in Helium

A review of characterization and physical property studies of metallic nanoparticles

The dc electrical resistance of films of Ag and Al soot which consists of fine particles has been measured between 1.5 and 300 K. The specimens are prepared by the gas evaporation method. The resistance is constant in the low temperature region, while it increases with temperature above a certain point. By analyzing the temperature dependence of the resistance, the Debye temperature for fine particles \(\varTheta_{P}\) was estimated. It was about 1/2∼2/3 of that of bulk metal for Al of the particles of size 150∼200A and 3/4∼5/6 for Ag of 100∼300A.

Temperature Dependence of Electrical Conductivity in Films of Fine Particles

It was reported in a previous paper that aluminum granular films prepared by means of gas evaporation in helium showed enhanced superconductivity. In the present experiment, a temperature dependence of D. C. electrical resistivities of these films is measured by means of a four contact method. It is found that absolute values of the resistance depend on the film thickness but the most of the films show temperature independent resistivity. These features are interpreted in terms of electronic mean free path and the particle size of the films.

Kazunari Ohshima

Papers

Temperature Dependence of Electrical Conductivity in Films of Fine Particles

D.C. Electric Conductivity in Films of Aluminum Fine Particles Prepared by Evaporation in Helium Gas

Superconductivity in Films of Aluminum Fine Particles Prepared by Evaporation in Helium Gas