Coarsening dynamics of striped patterns in thin granular layers under vertical vibration

Size dependent bipolar resistance switching of NiO nanodots for low-power and multi-state operation

NiO nanodots of various sizes were fabricated via anodic oxidation induced through atomic force microscopy (AFM) nanolithography on an 18 nm thick Ni thin film, and their resistance switching properties were investigated using conductive AFM. We found that NiO nanodots with a medium size of around 15 nm height showed clear bipolar resistance switching. A threshold switching was observed in the NiO nanodots with a larger size due to having a much thinner bottom Ni layer left after oxidation. By adjusting the range of the sweeping voltage, the high resistance state can be controlled to realize multi-state switching. The power consumption during the switching process induced by the AFM tip was found to be lower than the reported power values of the NiO thin film- or NiO nanowires-based resistance switching devices.

Ordered arrays of embedded Ga nanoparticles on patterned silicon substrates

We fabricate site-controlled, ordered arrays of embedded Ga nanoparticles on Si, using a combination of substrate patterning and molecular-beam epitaxial growth. The fabrication process consists of two steps. Ga droplets are initially nucleated in an ordered array of inverted pyramidal pits, and then partially crystallized by exposure to an As flux, which promotes the formation of a GaAs shell that seals the Ga nanoparticle within two semiconductor layers. The nanoparticle formation process has been investigated through a combination of extensive chemical and structural characterization and theoretical kinetic Monte Carlo simulations.

Jamming transition in a highly dense granular system under vertical vibration

The dynamics of the jamming transition in a three-dimensional granular system under vertical vibration is studied using diffusing-wave spectroscopy. When the maximum acceleration of the external vibration is large, the granular system behaves like a fluid, with the dynamic correlation function G (t) relaxing rapidly. As the acceleration of vibration approaches the gravitational acceleration g , the relaxation of G (t) slows down dramatically, and eventually stops. Thus the system undergoes a phase transition and behaves like a solid. Near the transition point, we find that the structural relaxation shows a stretched exponential behavior. This behavior is analogous to the behavior of supercooled liquids close to the glass transition.