Assembling nanostructures from DNA using a composite nanotweezers with a shape memory effect

The article demonstrates a technique for fabricating a structure with the inclusion of suspended DNA threads and manipulating them using composite nanotweezers with shape memory effect. This technique could be suitable for stretching of nanothin DNA-like conductive threads and for measuring their electrical conductivity, including the I-V characteristic directly in the electron microscope chamber, where the nanotweezers provide a two-sided clamping of the DNA tip, giving a stable nanocontact to the DNA bundle. Such contact, as a part of 1D nanostructure, is more reliable during manipulations with nanothreads than traditional measurements when a nanothread is touched by a thin needle, for example, in a scanning tunnel microscope.Comment: To be presented on IEEE 3M-NANO 201

Magnetostructural Phase Transition in Micro- and Nanosize Ni-Mn-Ga-Cu Alloys

Magnetostructural Phase Transition in Micro- and Nanosize Ni-Mn-Ga-Cu Alloy

Electron Mobility Sensor Scheme-Based on a Mach-Zehnder Interferometer Approach

This letter presents the use of a plasmonic sensing transducer on an embedded Mach-Zehnder interferometer (MZI) arm, allowing the sensing transducer to be formed through the stacked layers of the silicon-graphene-gold materials and embedded on an MZI arm with a gripping force to allow it to be used in sensing applications. The transduction process introduces an energy conversion between the input light and the excited electron mobility within the silicon and graphene layers. That way the electron drift velocity within the gold layer can drive the plasmonic wave group velocity induced through the interaction with the graphene layers, and consequently, the electron mobility in the gold layer increases. The driven electron mobility in the gold layer, caused by the plasmonic waves from graphene in the embedded sensing layers, will affect the electron output mobility, where the relative change in the phase of the light in the silicon can be seen at the output port of the MZI. To optimize the key parameters of such a system (especially input optical power and dimensions of the gold layer), simulations are performed at various input optical powers and the results are graphically represented. A maximum sensitivity of mV-1s-1 in electron mobility sensing is obtained through these simulations, designed to optimize the performance characteristics of the proposed sensor

Magnetocaloric and thermomagnetic properties of Ni2.18Mn0.82Ga Heusler alloy in high magnetic fields up to 140 kOe

Measurements of the adiabatic temperature change (ΔT) and the specific heat transfer (ΔQ) of Ni 2.18Mn0.82Ga Heusler alloy were taken in order to quantify the direct giant magnetocaloric effect of the alloy when it is in the vicinity of magneto-structural phase transition (PT) from paramagnetic austenite to ferromagnetic martensite, and their results are presented. A new vacuum calorimeter was used to simultaneously measure ΔT and ΔQ of magnetocaloric materials with a Bitter coil magnet in fields of up to H = 140 kOe. Other thermomagnetic properties of this alloy were investigated using standard differential scanning calorimetry and PPMS equipment. The maximal values of magnetocaloric effect in H = 140 kOe were found to be ΔT = 8.4 K at initial temperature 340 K and ΔQ = 4900 J/kg at 343 K. Using this direct method, we show that the alloy indeed demonstrates the largest value of ΔQ as compared with previously published results for direct measurements of magnetocaloric materials, even though at 140 kOe the magnetic field-induced magnetostructural PT is still not complete.Web of Science11716art. no. 16390