Journal of NanoScience in Advanced Materials

The Nano-Sized h-BN Addition into MgB2/Fe Superconducting Wires

2024-10-21T21:49:23+03:00

This paper reports on the effect of hexagonal boron nitride (h-BN) addition on the superconducting properties of in-situ iron (Fe) sheathed MgB2 bare and added wire samples (Φ=1.15 mm and 1.25 mm, respectively). The structural, electrical, mechanical and transport properties of MgB2 with 1 wt% h-BN addition compared to pure MgB2 wires were investigated for five different annealing temperatures. The results showed that the addition of nano-sized h-BN did not significantly affect the critical transition temperature for all wire samples, but relatively improved the wire uniformity, which contributed to the conduction properties of the wires.

Synthesis and Characterization of (3-Aminopropyl) triethoxysilane - Derived Silicon Nanoparticles Reduced with Ascorbic Acid

2024-10-25T08:51:13+03:00

This study explores the influence of synthesis parameters—reaction temperature, time, (3-Aminopropyl)triethoxysilane (APTES), and ascorbic acid (AA)—on the particle size and optical properties of silicon nanoparticles (SiNPs). A total of 22 experiments were conducted, employing UV-visible (UV-Vis) spectroscopy, photoluminescence (PL) spectroscopy, and transmission electron microscopy (TEM) for thorough characterization, with unique observations of color changes over time using periodic UV-Vis measurements. Initial studies at 40, 50, and 60°C for 30 to 120 minutes revealed that higher temperatures and aging enhanced UV absorbance, especially in the 200–250 nm range. A reaction duration of 60 minutes at 50°C optimized particle formation, with PL measurements indicating strong emission around 520 nm. Further tests showed that increased APTES levels shifted absorption to 350–450 nm, with dual peaks indicating specific silicon transitions. Over time, absorption in this range decreased, attributed to unreacted APTES. TEM images revealed spherical, well-dispersed particles with sizes influenced by APTES and AA levels. Higher AA concentrations improved particle formation, particularly in the 200–325 nm range, acting as a reducing agent. When APTES and AA were balanced, smaller particles (8.508±2.832 nm) formed, surrounded by amine-silica chains. These findings offer insights into tailoring SiNP properties for biotechnology, demonstrating the potential to achieve desired size, optical characteristics, and stability through precise parameter adjustments.

Effects of EG:CA Ratios on the Luminescence of BeO Ceramics by Sol-Gel Technique

2024-12-09T12:19:04+03:00

This study aims to investigate the effect of ethylene glycol (EG) and citric acid (CA), EG:CA, ratios on the structural, morphological and luminescence properties of BeO ceramics synthesized by sol-gel method. Structural and morphological characterization was done by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analyses, while Luminescence signals were characterized by Radioluminescence (RL), Thermoluminescence (TL) and Optical Stimulated Luminescence (OSL) techniques. XRD diffraction patterns showed that sol-gel synthesis was successful in the production of BeO ceramics and EG:CA ratios significantly changed the BeO structure. While the RL spectra of BeO ceramics synthesized by sol-gel method exhibited very sensitive emission peaks between 200 nm and 500 nm, characteristic of BeO, notable differences were observed in the dominant emission bands. Moreover, it has been proven that TL and OSL signals of samples synthesized using appropriate conditions can be enhanced for dosimetric purposes.

Metamaterial-Based Antenna Design with RCS Reduction Characteristics Using 2D Peanos Fractal

2024-08-09T11:10:04+03:00

This paper explores a stealth antenna design using a Peanos fractal structure and Square Split Ring Resonators (SSRRs) to reduce radar cross section (RCS) while maintaining performance. Advantages of the Peanos fractal geometry in miniaturization and electromagnetic wave manipulation are evaluated utilizing finite element analysis (FEA). Frequency Selective Surfaces (FSSs) with SSRRs enhance antenna performance by enabling unique electromagnetic properties. The simulation results of the study show that the periodic structure functions as a bandpass filter around 4.7 GHz and remains effective at various incidence angles. This research demonstrates the potential of Peanos fractal design for RCS reduction in stealth technology and advanced electromagnetic applications.

Structural and Magnetic Properties of Ag Nanoparticle (0.25%, 0.50% and 1%) doped YIG Thin Films

2024-06-04T09:34:30+03:00

This study investigated the structural, morphological and magnetic properties effects of silver (Ag) nanoparticle doping at low doping rates on Y3Fe5O12 (YIG) thin films. In the first stage of the study, Ag nanoparticles were synthesized by polyol method. In the second stage, both undoped YIG and 0.25%, 0.50% and 1% doped YIG thin films were grown on thermally oxidized Si substrates using sol-gel method. All films were crystallized crack-free by a two-step heat treatment process. XRD patterns confirm the YIG crystal structure and the Ag crystal structure, which is embedded in the structure without bonding with the YIG components. SEM images revealed that the Ag NPs synthesized by the polyol method have a homogeneous distribution. The surface morphology of the thin films showed that Ag NPs doping formed small islands on the surface morphology. While the saturation magnetization (Ms) values of the samples were very close to each other regardless of the doping rate, the coercive field values (Hc) increased remarkably with Ag doping. This value tends to decrease as the doping ratio increases. 0.25% AgNPs sample has the highest Hc value. Ms values between in-plane and out-of-plane measurements of the films increased with Ag concentration. As a result of all analyses, it was observed that all crack-free thin films were successfully obtained by optimizing the production parameters of the sol-gel method, which is a relatively inexpensive and easy method. Silver nanoparticle doping was found to improve the structural and magnetic properties of YIG thin films. It is predicted that this improvement will contribute to other properties of YIG thin films used in magneto-optical applications.