Engineering topics

Osin, Yu. N.

Publications and source records attributed to Osin, Yu. N..

5 records

DOE OSTI2019

Mediated electrosynthesis of silver nanoparticles in a two-phase water—isooctane system

Efficient electrosynthesis of silver nanoparticles (AgNPs) in bulk solution of a two-phase water—isooctane system is carried out by electrolysis in an undivided cell in the presence of methylviologen (MV{sup 2+}) used as a mediator. Silver nanoparticles are formed in the aqueous phase of the system as a result of the electroreduction of Ag{sup +} ions generated in situ by dissolving the Ag anode at potentials of the redox couple MV{sup 2+}/MV{sup ·+}. The obtained AgNPs are stabilized by an anionic surfactant, sodium dioctyl sulfosuccinate, and are distributed throughout both the aqueous and the organic phases. All the nanoparticles would transfer to the organic phase after the obtained solution was kept in the dark for 48 h. In addition to dissolution, the Ag anode undergoes dispersion during electrolysis, therefore the total current yield of the obtained AgNPs is 175%. According to electron microscopy, the formed AgNPs are polydisperse and their size ranges from 5 to 71 nm. A surface plasmon resonance of AgNPs in the solution obtained after electrolysis was observed in the region of 418–463 nm.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2019

Microscopic Examination of the Silicon Surface Subjected to High-Dose Silver Implantation

Low-energy (E = 30 keV) Ag{sup +} ions have been implanted into single-crystalline Si wafers (c-Si) with an implantation dose varying from 1.25 × 10{sup 15} to 1.5 × 10{sup 17} ions cm{sup –2} and an ion beam current density varying from 2 to 15 μA/cm{sup 2}. The surface morphology of implanted wafers has been examined using scanning electron microscopy, transmission electron microscopy, and atomic force microscopy, and their structure has been studied by means of reflection high-energy electron diffraction and elemental microanalysis. It has been shown that for minimal irradiation doses used in experiments, the surface layer of c-Si experiences amorphization. It has been found that when the implantation dose is in excess of the threshold value (~3.1 × 10{sup 15} ions cm{sup –2}), Ag nanoparticles uniformly distributed over the Si surface arise in the irradiated Si layer. At a dose exceeding 10{sup 17} ions cm{sup –2}, a porous Si structure is observed. In this case, the Ag nanoparticle size distribution becomes bimodal with coarse particles localized at the walls of Si pores.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2018

Raman Scattering of Light by Molecules of Methyl Orange Dye on the Surface of Silicon Containing Ion-Synthesized Silver Nanoparticles

The possibility of using a new composite material based on porous silicon containing silver nanoparticles and synthesized by means of a unique implantation nanotechnology as an optically sensitive material in biological and chemical sensors is tested experimentally. It is demonstrated that detection of small amounts of the studied organic substance (methyl orange dye) is possible due to the effect of surface-enhanced Raman scattering (SERS) from the molecules affected by the local electromagnetic field of the silver nanoparticles.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2018

Formation of Porous Germanium Layers by Silver-Ion Implantation

We propose a method for the formation of porous germanium (P-Ge) layers containing silver nanoparticles by means of high-dose implantation of low-energy Ag{sup +} ions into single-crystalline germanium (c-Ge). This is demonstrated by implantation of 30-keV Ag{sup +} ions into a polished c-Ge plate to a dose of 1.5 × 10{sup 17} ion/cm{sup 2} at an ion beam-current density of 5 μA/cm{sup 2}. Examination by high-resolution scanning electron microscopy (SEM), atomic-force microscopy (AFM), X-ray diffraction (XRD), energy-dispersive X-ray (EDX) microanalysis, and reflection high-energy electron diffraction (RHEED) showed that the implantation of silver ions into c-Ge surface led to the formation of a P-Ge layer with spongy structure comprising a network of interwoven nanofibers with an average diameter of ∼10–20 nm Ag nanoparticles on the ends of fibers. It is also established that the formation of pores during Ag{sup +} ion implantation is accompanied by effective sputtering of the Ge surface.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

DOE OSTI2018

Temperature sensor based on a polymer diffraction grating with silver nanoparticles

The method is suggested for producing an optical temperature noncontact sensor on a polymer polymethylmethacrylate (PMMA) substrate with a diffraction optical element formed by implanting low-energy high-dose silver ions through a surface mask. Ion implantation is performed at an energy of 30 keV, a radiation dose of 5.0 × 10{sup 16} ion cm{sup −}2 and an ion beam current density of 2 μA cm{sup −}2 through a surface metal mask having the form of grid with square periodical holes (cells) of size 25 μm. In the course of implantation, silver nanoparticles are produced in periodical unmasked domains of irradiated PMMA. Operation of the temperature sensor on diffraction microstructures made of polymer with silver nanoparticles is demonstrated in the range from 20 °C to 95 °C by testing it with a probe radiation of a He – Ne laser. (paper)

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗