Synthesis and Comparison of Boron Nitride Nanostructure Prepared on Silicon and Molybdenum Substrates by Laser Plasma Deposition Technique

2011 ◽  
Vol 1307 ◽  
Author(s):  
M. Sajjad ◽  
H. X. Zhang ◽  
P. X. Feng

ABSTRACTThe synthesis of boron nitride nanowires on silicon (Si) and nanorods on molybdenum (Mo) substrates at the same experimental conditions was composed. Fine tip nanowires with diameters around 50 nm were produced on Si substrates, whereas, nanorods with diameter around 100 nm were formed on Mo substrates. The change in length from 5 μm to 100 μm for nanowires and 0.2 μm to 0.8μm for nanorods following variation of substrate temperature were studied systematically.Scanning Electron Microscopy was used to analyze the surface images of BN nanowires and nanorods. Energy Dispersive X-Ray spectroscopy (EDS) was used to analyze boron and nitrogen concentration in the samples. The crystal structures of BN samples were investigated using Raman spectroscopy and x-ray diffraction. The experimental results showed that the nanorods are hexagonal mixed with cubic, whereas the nanowires are hexagonal.

2013 ◽  
Vol 631-632 ◽  
pp. 78-81 ◽  
Author(s):  
Xiao Jing Yang ◽  
Lan Lan Li ◽  
Xin Hua Zhang ◽  
Pan Shi ◽  
Yue Tian ◽  
...  

We reported on a convenient route to synthesize rhombohedra boron nitride (r-BN) micro-rod using urea (CO(NH2)2) and sodium borohydride (NaBH4) through thermal treatment at 1300 °C. The structure, morphology, and chemical composition of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). In order to determine the phase composition and abundance of the as-synthsized simples, Rietveld refinement has been performed to analyze the XRD data using the Rietan-2000 program. The results show that the abundance of r-BN is about 90.6 wt % and h-BN is 9.4 wt % deduced from Reitveld refinement.


2015 ◽  
Vol 1120-1121 ◽  
pp. 572-575
Author(s):  
Hong Wei Liu ◽  
Feng Wang ◽  
Qiang Zhang ◽  
Xi Wu Li ◽  
Zhi Hui Li ◽  
...  

An innovative spray deposition technique has been applied to produce in situ TiB2/Zn-30Al-1Cu composites. The microstructures of the spray-deposited composite were studied using optical microscopy, scanning electron microscopy, and X-ray diffraction. Both theoretical and experimental results have shown that the TiB2particulates are formed in the microstructure. It was found that the TiB2particles were distributed in Zn-30Al-1Cu matrix uniformly, and the TiB2particles are about 2 μm in size. Moreover, the presence of the TiB2particles was led to increasing of α’ phase with less 2 μm size in the composites which have a tendency to decompose to α+η structure.


2009 ◽  
Vol 24 (1) ◽  
pp. 58-65 ◽  
Author(s):  
Yange Zhang ◽  
Zhi Zheng ◽  
Ka Wai Wong ◽  
Fengling Yang ◽  
Zude Zhang

The α-, β-, and δ-MnO2 with various morphologies have been synthesized by a novel redox system of KMnO4 and CuCl with HCl added under a hydrothermal condition. The resultant MnO2 products have been characterized by x-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Upon control of reaction temperature and duration, it was observed that MnO2 polymorphs of different morphology (e.g., flowery δ-MnO2, β-MnO2 nanowires and octahedrons, α-MnO2 nanowires) can be prepared in an adjustable manner. The phenomenon is mainly attributed to the effect of cuprous ions controllably released from CuCl by the action of HCl at different experimental conditions. The corresponding formation mechanism for the MnO2 crystals will also be proposed and discussed.


1993 ◽  
Vol 8 (1) ◽  
pp. 18-24 ◽  
Author(s):  
K. D. Rogers ◽  
D. Cossins

The thermal decomposition of aqueous manganese nitrate has been studied under a range of experimental conditions to scientifically assess the pyrolysis processes employed by the tantalum capacitor industry. The crystalline phase and form of the manganese oxides produced are compared by X-ray diffraction and scanning electron microscopy. Those experimental conditions producing materials with the lowest resistivity are identified. The technological significance of the decomposition process is discussed and initial results from a novel pyrolysis technique are presented.


2007 ◽  
Vol 119 ◽  
pp. 79-82
Author(s):  
Hyoun Woo Kim ◽  
S.H. Shim ◽  
Jong Woo Lee

We have demonstrated the growth of SiOx nanowires by the simple heating of the Au-coated Si substrates. We used X-ray diffraction, scanning electron microscopy, energy dispersive x-ray spectroscopy, and transmission electron microscopy to characterize the samples. The as-synthesized SiOx nanowires had amorphous structures with diameters in the range of 10-70 nm. We have discussed the possible growth mechanism.


2014 ◽  
Vol 680 ◽  
pp. 38-41
Author(s):  
Dheerachai Polsongkram ◽  
Pattanasuk Chamninok ◽  
Suchaowadee Changsakul ◽  
Atipong Sriputhorn ◽  
Supakorn Pukird

We studied the effect of time and temperature for preparation of SnO2 nanostructures by chemical vapor deposit methods. SnO2 nanostructures were synthesized using Sn powder with carbon charcoal as starting materials. The source materials and Si substrates were heated with various times, temperatures under atmosphere of nitrogen and oxygen. The synthesized products were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) techniques. The results showed the nanostructures of prepared products were very uniformly of SnO2 nanowires with diameter about 100-300 nm and length around more 1-2 μm depending on times and temperatures.


2012 ◽  
Vol 734 ◽  
pp. 237-246 ◽  
Author(s):  
Pankaj ◽  
Shikha Goyal

The ultrasonic decolourisation of two commonly used textile dyes, Acid Red 114 (AR 114) and Reactive Blue 21 (RB 21), with different chromophoric groups, azo and phthalocyanine respectively, has been studied using TiO2 (consisting of mixture of crystalline and amorphous phases) in the presence of rare earths ions (Pr3+, Ce4+). The characterisation of TiO2 has been done through X-ray diffraction (XRD), scanning electron microscopy (SEM), Raman spectroscopy, diffuse reflectance spectroscopy (DRS) and N2 adsorption techniques. The decolourisation of AR 114 was faster than for RB 21 under all the experimental conditions. Almost complete decolourisation of both dyes was achieved in 5 min in the presence of US+TiO2+Ce. Ce4+ was found to be more effective than Pr3+. The decolourisation reaction followed second order kinetics. The effects of initial dye concentration and amount of TiO2 on the decolourisation of dyes have been found to be in the order; US+TiO2+Ce > US+TiO2+Pr > US+Ce > US+Pr > US+TiO2 > TiO2 >US. The decolourisation rate increased with increase in TiO2 amount and decreased with increase in initial dye concentration.


2006 ◽  
Vol 20 (12) ◽  
pp. 715-723
Author(s):  
JIAN XU ◽  
WEIHAO XIONG ◽  
AIXIANG ZENG

Electroless deposition of Ni-P alloys on cenospheres is demonstrated in the present investigation. AgNO 3 is used as an activator to replace the conventional PdCl 2 activator and [Formula: see text] in the coating bath is used as the reducing agent to replace Sn 2+ in order to lower the overall cost of the coating process. The coated cenospheres are characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and powder X-ray diffraction (XRD). It shows that Ni-P alloys uniformly deposit on the surface of the cenospheres under experimental conditions. The possible mechanism of electroless Ni-P alloys coating of cenospheres by using silver as the catalyst is suggested.


2014 ◽  
Vol 602-603 ◽  
pp. 499-502 ◽  
Author(s):  
Yuan Yuan Zhu ◽  
Shang Sheng Li ◽  
Liang Li ◽  
Ai Guo Zhou

Ternary carbide Ti3SiC2 is a good binder to make superhard composites with diamonds or cubic boron nitride. Superhard composites are normally made at high temperature and under high pressure around 5 GPa to avoid the phase transformation of diamonds or cubic boron nitride. This paper researched the synthesis of Ti3SiC2 from the powders of Ti, Si, and graphite by a cubic presser under 1 GPa to 4 GPa at 1400°C. The decomposition of Ti3SiC2 under 5GPa at 1400°C was also researched. From X-ray diffraction (XRD) and scanning electron microscopy (SEM) results, Ti3SiC2 was synthesized in 30 min under 1 GPa at 1400°C. The impurities were TiSi2, Ti5Si3Cx, and TiC. As the pressure increased from 1GPa to 4GPa, less Ti3SiC2 more TiSi2 was synthesized. Therefore, high presser > 1GPa is unfavorable for the synthesis of Ti3SiC2. After treated under 5GPa at 1400°C, pure Ti3SiC2 was decomposed.


2013 ◽  
Vol 594-595 ◽  
pp. 306-310 ◽  
Author(s):  
Sri Asliza Md Amin ◽  
Kasmuin Mohd Zaheruddin ◽  
Azmi Rahmat ◽  
Shamsul Baharin Jamaludin ◽  
R.A. Khairel

Ni deposited on HA powder was prepared by electroless plating process without sensitization and activation treatment. The deposited powder obtained was characterized by energy dispersive spectroscopy (EDX) and x-ray diffraction (XRD). The microstructure and hardness of the sintered powder were examined by scanning electron microscopy (SEM) and Vickers hardness respectively. From the result, the nickel existence in the deposition was confirmed by the EDX analysis. The diffraction peaks at 44.5 and 64.7o (2θ) of planes (111) and (211) respectively were belong to nickel. Nickel are homogeneously dispersed in HA matrix with grain size between 0.25-2μm after sintered at 1250°C. The improvement of 93% and 180% in average hardness and flexural strength respectively were achieved with nickel presence in HA compared to pure HA.


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