32 research outputs found
Decoration of MoSI Nanowires with Platinum Nanoparticles and Transformation into Molybdenum-nanowire Nased Networks
In this communication, we present solution-based coating procedure of MoSI nanowires (NW) with
platinum nanoparticles. The average particle diameter was found to be around 2.82 nm, showing a narrow
size distribution. This single-step in situ reduction method at room temperature in water solution can
easily be applied for large-scale applications. We also prepared two-dimensional networks of MoSI NW
bundles by deposition via spraying from a purified stable dispersion in acetonitrile onto NaCl crystals and
nonconductive silicon wafer with pre-assembled molybdenum electrodes. The formation of a conductive
molybdenum network was achieved by annealing in hydrogen due to coalescence of the templates MoSI
bundles during transformation. Stable water dispersion of molybdenum NW network was prepared by
simply dissolving the NaCl substrate with molybdenum network on the surface.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516
Decoration of MoSI Nanowires with Platinum Nanoparticles and Transformation into Molybdenum-nanowire Nased Networks
In this communication, we present solution-based coating procedure of MoSI nanowires (NW) with
platinum nanoparticles. The average particle diameter was found to be around 2.82 nm, showing a narrow
size distribution. This single-step in situ reduction method at room temperature in water solution can
easily be applied for large-scale applications. We also prepared two-dimensional networks of MoSI NW
bundles by deposition via spraying from a purified stable dispersion in acetonitrile onto NaCl crystals and
nonconductive silicon wafer with pre-assembled molybdenum electrodes. The formation of a conductive
molybdenum network was achieved by annealing in hydrogen due to coalescence of the templates MoSI
bundles during transformation. Stable water dispersion of molybdenum NW network was prepared by
simply dissolving the NaCl substrate with molybdenum network on the surface.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3516
Template Synthesis of MoN Superconducting Nanowires
We have demonstrated a new facile method for the controllable synthesis of high quality single-phase MoN nanowires with Tc 10.5 K from Mo6S2I8 nanowires templates. The MoN nanowire diameters were controlled exclusively by the Mo6S2I8 nanowires template diameters, which were in the range between several tens and several hundreds of nanometers in this study. Furthermore, we have demonstrated that Ohmic contacts can be prepared on δ3-MoN nanowires with ion beam induced platinum deposition using an FIB, allowing detailed characterization of the superconducting and transport properties of MoN nanowires. In addition, we have demonstrated straightforward synthesis of porous δ3-MoN nanowires and nanotubes from MoS2 nanotubes. X-ray diffraction, scanning electron microscopy with wave dispersive analysis, transmission electron microscopy, four probe electrical transport measurements and SQUID were used to characterize the starting nanowires and nanotubes and the final products
Critical exponents at the ferromagnetic transition in tetrakis(diethylamino)ethylene-C (TDAE-C)
Critical exponents at the ferromagnetic transition were measured for the
first time in an organic ferromagnetic material tetrakis(dimethylamino)ethylene
fullerene[60] (TDAE-C). From a complete magnetization-temperature-field
data set near we determine the susceptibility and
magnetization critical exponents and respectively, and the field vs. magnetization exponent at of
. Hyperscaling is found to be violated by , suggesting that the onset of ferromagnetism can be
related to percolation of a particular contact configuration of C
molecular orientations.Comment: 5 pages, including 3 figures; to appear in Phys. Rev. Let
The polymer phase of the TDAE-C organic ferromagnet
The high-pressure Electron Spin Resonance (ESR) measurements were preformed
on TDAE-C single crystals and stability of the polymeric phase was
established in the parameter space. At 7 kbar the system undergoes a
ferromagnetic to paramagnetic phase transition due to the pressure-induced
polymerization. The polymeric phase remains stable after the pressure release.
The depolymerization of the pressure-induced phase was observed at the
temperature of 520 K. Below room temperature, the polymeric phase behaves as a
simple Curie-type insulator with one unpaired electron spin per chemical
formula. The TDAE donor-related unpaired electron spins, formerly
ESR-silent, become active above the temperature of 320 K and the Curie-Weiss
behavior is re-established.Comment: Submitted to Phys. Rev.
Molecular nitrogen in N doped TiO2 nanoribbons
The nitrogen doping of TiO2 nanoribbons during the thermal transformation of hydrogen titanate nanoribbons HTiNRs between 400 and 650 C in a dynamic ammonia atmosphere was investigated using X ray photoelectron spectroscopy XPS , transmission X ray microscopy combined with near edge X ray absorption fine structure spectroscopy NEXAFS TXM , X ray diffraction XRD and electron paramagnetic resonance measurements EPR . Comprehensive structural characterizations have revealed that for a calcination temperature of 400 C, the HTiNRs transform into pure monoclinic TiO2 b phase TiO2 B whereas at higher calcination temperatures 580 and 650 C a mixture of TiO2 B and anatase is obtained. XPS and EPR results clearly reveal the nitrogen doping of TiO2 nanoribbons and that, depending on the calcination temperature, nitrogen atoms occupy interstitial and substitutional sites. Moreover, in samples calcined at 580 and 650 C the presence of N2 like species in the HTiNRs was detected by NEXAFS TXM. These species are trapped in the HTiNRs structure. EPR measurements upon light illumination have disclosed the generation of photoexcited states which implies that nitrogen has an important effect on the electronic structure of N doped TiO
The MoS2 Nanotubes with Defect-Controlled Electric Properties
We describe a two-step synthesis of pure multiwall MoS2 nanotubes with a high degree of homogeneity in size. The Mo6S4I6 nanowires grown directly from elements under temperature gradient conditions in hedgehog-like assemblies were used as precursor material. Transformation in argon-H2S/H2 mixture leads to the MoS2 nanotubes still grouped in hedgehog-like morphology. The described method enables a large-scale production of MoS2 nanotubes and their size control. X-ray diffraction, optical absorption and Raman spectroscopy, scanning electron microscopy with wave dispersive analysis, and transmission electron microscopy were used to characterize the starting Mo6S4I6 nanowires and the MoS2 nanotubes. The unit cell parameters of the Mo6S4I6 phase are proposed. Blue shift in optical absorbance and metallic behavior of MoS2 nanotubes in two-probe measurement are explained by a high defect concentration