No abstract

Single-crystal nanoparticles of silicon, several tens of nm in diameter, may be suitable as building blocks for single-nanoparticle electronic devices. Previous studies of nanoparticles produced in low-pressure plasmas have demonstrated the synthesis nanocrystals of 2-10 nm diameter but larger particles were amorphous or polycrystalline.This work reports the use of a constricted, filamentary capacitively coupled low-pressure plasma to produce single-crystal silicon nanoparticles with diameters between 20-80 nm.Particles are highly oriented with predominant cubic shape. The particle size distribution is rather monodisperse. Electron microscopy studies confirm that the nanoparticles are highly oriented diamond-cubic silicon.8ZH .RUWVKDJHQ HW DO

Individual nanoparticles of silicon and titanium having diameters in the range of 40-140 nm have been repeatedly compressed by a nanoindenter. Even at low loads, the small tip-particle and particle-substrate contacts generate extreme pressures within the confined particle, influencing its stiffness and fracture toughness. The effect of these high pressures on the measured modulus is taken into account by invoking a Murnaghan equation-of-state-based analysis. Fracture toughness of the silicon particles is found to increase by a factor of 4 in compression for a 40-nm-diam particle when compared to bulk silicon. Additionally, strain energy release rates increase by more than an order of magnitude for particles of this size when compared to bulk Si.

Single-crystal nanoparticles of silicon, several tens of nm in diameter, may be suitable as building blocks for single-nanoparticle electronic devices. Previous studies of nanoparticles produced in low-pressure plasmas have demonstrated the synthesis nanocrystals of 2–10 nm diameter but larger particles were amorphous or polycrystalline. This work reports the use of an inductively coupled low-pressure plasma to produce single-crystal silicon nanoparticles with diameters between 20 and 80 nm. Electron microscopy studies confirm that the nanoparticles are highly oriented diamond-cubic silicon.

Layered double hydroxide (LDH)-monodispersed 4-nm CdSe nanoparticle composites were prepared through restacking of layers of colloidally dispersed delaminated LDH in the presence of CdSe nanoparticles in 1-butanol. The composites exhibit a blue shift for CdSe absorption, which increases with a decrease in nanoparticle content. The observed blue shift is due to the interaction of the quantum dots with the LDH layers, which leads to surface modification of the nanoparticles.