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M Forero

Publications and source records attributed to M Forero.

3 recordsLinked to original sources

Scanned probe microscopy of electronic transport in carbon nanotubes.

We use electrostatic force microscopy and scanned gate microscopy to probe the conducting properties of carbon nanotubes at room temperature. Multiwalled carbon nanotubes are shown to be diffusive conductors, while metallic single-walled carbon nanotubes are ballistic conductors over micron lengths. Semiconducting single-walled carbon nanotubes are shown to have a series of large barriers to conduction along their length. These measurements are also used to probe the contact resistance and locate breaks in carbon nanotube circuits.

Journal Article↗

Crossed nanotube junctions

Junctions consisting of two crossed single-walled carbon nanotubes were fabricated with electrical contacts at each end of each nanotube. The individual nanotubes were identified as metallic (M) or semiconducting (S), based on their two-terminal conductances; MM, MS, and SS four-terminal devices were studied. The MM and SS junctions had high conductances, on the order of 0.1 e(2)/h (where e is the electron charge and h is Planck's constant). For an MS junction, the semiconducting nanotube was depleted at the junction by the metallic nanotube, forming a rectifying Schottky barrier. We used two- and three-terminal experiments to fully characterize this junction.

Journal Article↗

Distribution of liposomes in tuberculous mice.

The dynamics of the distribution of liposomes for use as drug carriers for the treatment of tuberculosis is studied. While the free radiolabel injected into mice was rapidly excreted by the kidneys, the same label trapped within liposomes was retained for longer periods in the liver, spleen and lung. There were variations in the distribution and retention times of liposomes of different composition. When the distribution of liposomes in healthy and tuberculous mice was compared, a greater accumulation in the liver, spleen and lungs of healthy mice was observed, although the retention time in tuberculous mice was longer. These findings merit consideration in the design of therapies based on liposome-entrapped drugs as the dynamics of distribution and retention differ between normal and infected animals.

Animals↗