ABSTRACT
In the field of spintronics, the archetype solid-state two-terminal device is the spin valve, where the resistance is controlled by the magnetization configuration. We show here how this concept of spin-dependent switch can be extended to magnetic electrodes in solution, by magnetic control of their chemical environment. Appropriate nanoscale design allows a huge enhancement of the magnetic force field experienced by paramagnetic molecular species in solutions, which changes between repulsive and attractive on changing the electrodes' magnetic orientations. Specifically, the field gradient force created within a sub-100-nm-sized nanogap separating two magnetic electrodes can be reversed by changing the orientation of the electrodes' magnetization relative to the current flowing between the electrodes. This can result in a breaking or making of an electric nanocontact, with a change of resistance by a factor of up to 10(3). The results reveal how an external field can impact chemical equilibrium in the vicinity of nanoscale magnetic circuits.
ABSTRACT
A rigid S-functionalized metalloligand is used to pair Janus Au-coated silica microspheres and the resulting assemblies are assessed with optical microscopy. New Pd complexes provide stable molecular interconnects, and the metal centre controls the structure of the linker and provides the desired rigidity, by virtue of its well-established coordination chemistry.
ABSTRACT
Charge transport in networks of nanoparticles linked by molecular spacers is investigated. Remarkably, in the regime where cotunneling dominates, the molecular signature of a device is strongly enhanced. We demonstrate that the resistance ratio of identical networks with different molecular spacers increases dramatically, from an initial value of 50 up to 10(5) , upon entering the cotunneling regime. Our work shows that intrinsic molecular properties can be amplified through nanoscale engineering.
ABSTRACT
The construction of soft and processable organic material able to display metallic conduction properties-a large density of freely moving charges-is a major challenge for electronics. Films of doped conjugated polymers are widely used as semiconductor devices, but metallic-type transport in the bulk of such materials remains extremely rare. On the other hand, single-walled carbon nanotubes can exhibit remarkably low contact resistances with related large currents, but are intrinsically very difficult to isolate and process. Here, we describe the self-assembly of supramolecular organic nanowires between two metallic electrodes, from a solution of triarylamine derivative, under the simultaneous action of light and electric field triggers. They exhibit a combination of large conductivity values (>5 × 10(3) S m(-1)) and a low interface resistance (<2 × 10(-4) Ω m). Moreover, the resistance of nanowires in series with metal interfaces systematically decreases when the temperature is lowered to 1.5 K, revealing an intrinsic metallic behaviour.
Subject(s)
Light , Metals/chemistry , Nanowires , Electricity , Microscopy, Atomic Force , Polymers/chemistryABSTRACT
Sub-micron-sized [Fe(Htrz)(2)(trz)](BF(4))·H(2)O nanoparticles that exhibit a spin crossover transition are positioned between Au electrodes with sub-100 nm separation. After voltage poling, samples exhibit unexpected large conductivity, with photoconductance and photovoltaic behavior.