EFFECT OF AMMONIA SOLUTION ON COMPOSITION, STRUCTURE AND MAGNETIC PROPERTIES OF CHEMICALLY PREPARED Co-B NANO-PARTICLES

2012 ◽  
Vol 05 ◽  
pp. 134-141
Author(s):  
HOOMAN SABAROU ◽  
ABOLGHASEM ATAIE

In this study, the effect of ammonia solution addition as a pH adjusting component on the thermal behavior, phase composition, morphology, and magnetic properties of reduced Co - B nano-particles fabricated by chemical reduction route have been studied using DSC, XRD, SEM, and VSM techniques, respectively. Chemical composition of the samples was measured by ICP. The ICP results showed that basic pH of reagent solution, derived from utilizing ammonia solution, caused the boron content to decrease. XRD results indicated an amorphous structure for both samples synthesized with and without ammonia solution. Analysis of the DSC results showed that crystallization behavior has dramatically altered, owing to utilize ammonia solution. While the sample synthesized without ammonia solution showed three distinctive exothermic peaks at 216,470, and 540°C, the sample synthesized in the presence of ammonia solution exhibited only two exothermic peaks at 235 and 470°C and one endothermic peak at 370°C. SEM images reveal that the samples have a net- like morphology and the net is formed by many interconnected spherical fine particles with sizes less than 100 nm. Saturation magnetization of the sample synthesized in the presence of ammonia solution has improved significantly, probably due to the less amount of boron.

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.


2021 ◽  
Author(s):  
Anjali Shrivastava ◽  
Ashwani Kumar Shrivastava

Abstract Co-precipitation technique was adopted to synthesize gadolinium doped manganese-zinc ferrite nano particles with varying concentration 0, 0.1, 0.2 and 0.3. XRD patterns authenticated the ferrite innovate in the as-prepared samples. The lattice parameter, crystallite size, lattice strain and x-ray density has been calculated. The crystallite size is comes bent on be around 5 nm. The FTIR spectra reveal that every one the functional groups are present within the material. SEM images are accustomed to indicate the morphological characteristics of the as-prepared samples. Magnetic properties show the decrease in saturation magnetization from 37.57emu/g to 30.15emu/g with reference to increase in gadolinium doping from 0.1 to 0.3.


2001 ◽  
Vol 226-230 ◽  
pp. 1933-1935 ◽  
Author(s):  
L.C. Varanda ◽  
M. Jafelicci ◽  
G.F. Goya

2010 ◽  
Vol 174 ◽  
pp. 405-408 ◽  
Author(s):  
Bao Lin Tang ◽  
Guang Xue Chen ◽  
Qi Feng Chen ◽  
Jing Lei Tai

Printing electronics technology promotes the application of conductive ink. In this paper, the manufacture of nano-sliver conductive ink is investigated. First, Spherical silver nano-particles were reduced from silver nitrate solution by liquid chemical reduction method, with hydrazine hydrate as reductant and PVP as surface-protection reagent. SEM was used to characterize the morphology of silver powders, and the mean particles size is 62.79 nm. Then, conductive ink was prepared with nano-silver particles made in this research as conductive fillers, polyurethane resin and acrylic resin as binders, and stearic acid as dispersant. In the last, the conductive ink was printed on the PCB substrate by screening printing. After the ink is dried, conductivity, abrasion resistance, and adhesion were tested. The experiment results shows that the order of sheet resistivity magnitude is 10-4Ω•m, the number of rubbing fastness is more than 6000, and the adhesion can be resisted repeatedly to tape tear.


2014 ◽  
Vol 896 ◽  
pp. 245-248 ◽  
Author(s):  
Candra Kurniawan ◽  
Hayati M.A. Sholihat ◽  
Kemas Ahmad Zaini Thosin ◽  
Muljadi ◽  
Prijo Sardjono

Despite of its excellence magnetic quality, one of the critical properties of PrFeB based permanent magnet is a low corrosion resistance so it can be oxidized easily which can reduce its magnetic properties. In this study, Nickel coating has been performed for bonded PrFeB magnet by the electroplating method using Nickel-Watts bath-type as the electrolyte to improve the corrosion resistance. The varying amount of the electrolyte compounds used to have the optimized composition indicated by the corrosion resistance measurement. The solution composition used was NiSO4 (230-380 g/L), NiCl2 (30-60 g/L), and H3BO3 (30 and 45 g/L) with a fixed value of other parameters. Characterization used including the immersion corrosion test, microstructure analysis, and magnetic properties. Based on the corrosion rate measurement, the highest corrosion resistant of Nickel coated PrFeB magnet achieved from the electrolyte composition of NiSO4: NiCl2: H3BO3 = 380: 60: 30 g/L with a plating time and current density (J) of 60 minutes and 40 mA/cm2 respectively. The corrosion rate data showed that the Nickel metal coating can improve the corrosion resistance of bonded PrFeB magnet up to 29 times than of the substrate. The SEM images showed that the thickness of the Nickel coating on the optimum electrolyte composition was in average value of 35.1 µm. The overall samples has a magnetic remanence value (Br) reached ≥ 6 kG, so it has enough properties to be applied in devices such as generators and electric motors.


Sign in / Sign up

Export Citation Format

Share Document