scholarly journals MAGNETIC AND THERMAL PROPERTIES OF NANOMATERIALS BASED ON HIGHLY BRANCHED FERROCENE-CONTAINING POLYMERS

2018 ◽  
Vol 13 (5) ◽  
pp. 49-57 ◽  
Author(s):  
R. A. Dvorikov ◽  
V. A. Vasnev ◽  
А. А. Korlukov ◽  
М. I. Buzin
Keyword(s):  
Ir Spectroscopy ◽  
Magnetic Particles ◽  
Heating Temperature ◽  
Treatment Temperature ◽  
Magnetic Nanomaterials ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Average Size ◽  
Principal Possibility

New magnetic nanomaterials with magnetization up to 32 Gs·cm3/g were synthesized from highly branched ferrocene-containing polymers by thermal structural transformations in a field of 2.5 kOe. The structure and properties of the prepared polymers were studied by IR spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analyses. According to IR spectroscopy the content of 1,3,5-substituted benzene rings in the ferrocene-containing polymer increases at 500°C. X-ray diffraction study showed that iron in such a sample is present exclusively in the form of Fe3O4 magnetite. As the heating temperature increased to 600°C, the composition of the samples became more complex: along with magnetite they contain cementite Fe3C and wustite FeO.97O. The magnetization of the ferrocene-containing polymer depends on the synthesis and heat treatment temperature. For a sample synthesized at 140°C the formation of a magnetically ordered phase begins at 500°C, and at 800°C the magnetization reaches a maximum value of 32 Gs·cm3/g. The average size of magnetic particles according to TEM analysis was 8-26 nm. The principal possibility of controlling the size and composition of the nanoparticles, as well as their magnetization depending on the conditions of production and the temperature of polymer structuring is shown. The obtained results provide a good basis for the directed synthesis of magnetic ferrocene-containing polymers with preset characteristics.

scholarly journals Synthesis and Characterization of Cysteine-Capped CdSe Nanoparticles Using an Alternative of Selenium

2019 ◽  
Vol 31 (11) ◽  
pp. 2457-2460
Author(s):  
K.E. Mokubung ◽  
M.J. Moloto ◽  
K.P. Mubiayi ◽  
N. Moloto
Keyword(s):  
Cdse Nanoparticles ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Prepared Nanoparticles ◽  
Transmission Electron ◽  
Different Temperatures ◽  
Xrd Patterns ◽  
Average Size

Present work reports synthesis of L-cysteine capped CdSe nanoparticles at different temperatures via an aqueous medium, non-toxic and green colloidal route. Cadmium chloride (CdCl2·5H2O) and sodium selenite (Na2SeO3) were used as cadmium and selenium sources respectively. The prepared nanoparticles are characterized by UV-visible absorption and photoluminescence spectroscopy, Fourier transform infrared, X-ray diffraction and transmission electron microscopy. The XRD patterns confirm a cubic phase structure of the prepared nanoparticles at 55, 75 and 95 ºC, respectively. The TEM analysis, optical absorption and photoluminescence spectra shows epitaxial growth of CdSe nanoparticles as the temperature increases with average size diameter of 4.12 ± 0.32, 5.02 ± 0.234 and 5.53 ± 0.321 nm for 55, 75 and 95 ºC, respectively.

scholarly journals X-ray diffraction study of the elastic properties of jagged spherical CdS nanocrystals

2020 ◽  
Vol 38 (2) ◽  
pp. 271-278
Author(s):  
Pijush Ch. Dey ◽  
Sumit Sarkar ◽  
Ratan Das
Keyword(s):  
Elastic Properties ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
X Ray ◽  
Cds Nanocrystals ◽  
Peak Broadening ◽  
Transmission Electron ◽  
Strain Stress ◽  
The Individual ◽  
Average Size

AbstractIn this work, jagged spherical CdS nanocrystals have been synthesized by chemical method to study their elastic properties. The synthesized CdS nanocrystal has been characterized by transmission electron microscopy (TEM) and X-ray diffraction (XRD). The transmission electron microscope images show that the average size of the nanocrystal is 100 nm approximately. X-ray diffraction (XRD) study confirms that the CdS nanocrystals are in cubic zinc blende structure. The size calculated from the XRD is consistent with the average size obtained from the TEM analysis. The XRD data have been analyzed to study the elastic properties of the jagged spherical CdS nanocrystals, such as intrinsic strain, stress and energy density, using WilliamsonHall plot method. Williamson-Hall method and size-strain plot (SSP) have been used to study the individual effect of crystalline size and lattice strain on the peak broadening of the jagged spherical CdS nanocrystals. Size-strain plot (SSP) and root mean square (RMS) strain further confirm the results obtained from W-H plots.

Hydrothermal Synthesis and UV Absorption Property of Firewood-Like CeO2 Nanostructures

2012 ◽  
Vol 557-559 ◽  
pp. 577-580
Author(s):  
Yun Ling Zou ◽  
Yan Li ◽  
Nan Zhang ◽  
Qing Jun Zhou
Keyword(s):  
Electron Microscopy ◽  
Uv Absorption ◽  
Absorption Property ◽  
X Ray Diffraction ◽  
Tem Analysis ◽  
Transmission Electron ◽  
Good Crystallinity ◽  
Fluorite Type ◽  
Average Size ◽  
First Time

In this paper, we reported that firewood-like CeO2nanostructures were synthesized via hydrothermal method in the present of cetyltrimethylammonium bromide (CTAB) for the first time. X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) were used to characterize the as-obtained sample. The UV absorption property of the product was investigated by UV-vis spectrophotometry. XRD result shows that the product was a cubic fluorite-type CeO2phase with good crystallinity. FE-SEM and TEM analysis indicate that the firewood-like CeO2nanostructures were composed of CeO2nanoparticles with the average size of about 6-10 nm. The CeO2shows excellent UV absorption for that the transmittance (T %) of the sample in the UV region almost equal to zero.

scholarly journals Carbon-coated magnetic particles increase tissue temperatures after laser irradiation

2015 ◽  
Vol 08 (05) ◽  
pp. 1550018 ◽  
Author(s):  
Shupeng Liu ◽  
Na Chen ◽  
Fufei Pang ◽  
Zhengyi Chen ◽  
Tingyun Wang
Keyword(s):  
Laser Irradiation ◽  
Magnetic Particles ◽  
Laser Energy ◽  
Thermal Therapy ◽  
Vibrating Sample Magnetometer ◽  
X Ray Diffraction ◽  
X Ray ◽  
Fbg Sensor ◽  
Transmission Electron ◽  
Carbon Coated

Purpose: This work focused on the investigation the hyperthermia performance of the carbon-coated magnetic particles (CCMPs) in laser-induced hyperthermia. Materials and methods: We prepared CCMPs using the organic carbonization method, and then characterized them with transmission electron microscopy (TEM), ultraviolet-visible (UV-Vis) spectrophotometry, vibrating sample magnetometer (VSM) and X-ray diffraction (XRD). In order to evaluate their performance in hyperthermia, the CCMPs were tested in laser-induced thermal therapy (LITT) experiments, in which we employed a fully distributed fiber Bragg grating (FBG) sensor to profile the tissue's dynamic temperature change under laser irradiation in real time. Results: The sizes of prepared CCMPs were about several micrometers, and the LITT results show that the tissue injected with the CCMPs absorbed more laser energy, and its temperature increased faster than the contrast tissue without CCMPs. Conclusions: The CCMPs may be of great help in hyperthermia applications.

The effect of silver concentration and calcination temperature on structural and optical properties of ZnO:Ag nanoparticles

2015 ◽  
Vol 29 (01) ◽  
pp. 1450254 ◽  
Author(s):  
M. Shayani Rad ◽  
A. Kompany ◽  
A. Khorsand Zak ◽  
M. E. Abrishami
Keyword(s):  
Calcination Temperature ◽  
Sol Gel ◽  
Visible Emission ◽  
X Ray Diffraction ◽  
Ag Nps ◽  
Zno Nps ◽  
Calcination Temperatures ◽  
Transmission Electron ◽  
Xrd Patterns ◽  
Average Size

Pure and silver added zinc oxide nanoparticles ( ZnO -NPs and ZnO : Ag -NPs) were synthesized through a modified sol–gel method. The prepared samples were characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy. In the XRD patterns, silver diffracted peaks were also observed for the samples synthesized at different calcination temperatures of 500°C, 700°C, 900°C except 1100°C, in addition to ZnO . TEM images indicated that the average size of ZnO : Ag -NPs increases with the amount of Ag concentration. The PL spectra of the samples revealed that the increase of Ag concentration results in the increase of the visible emission intensity, whereas by increasing the calcination temperature the intensity of visible emission of the samples decreases.

Effect of Sonication Time and Calcination Temperature on Physical Properties of Titanium Dioxide Synthesized via Sonochemical-Assisted Process

2013 ◽  
Vol 802 ◽  
pp. 252-256 ◽  
Author(s):  
Chokchai Kahattha ◽  
Naratip Vittayakorn ◽  
Wisanu Pecharapa
Keyword(s):  
Titanium Dioxide ◽  
Electron Microscope ◽  
Titanium Dioxide Nanoparticles ◽  
Anatase Phase ◽  
Titanium Isopropoxide ◽  
Treatment Temperature ◽  
Sonication Time ◽  
X Ray Diffraction ◽  
Calcination Process ◽  
Transmission Electron

Titanium dioxide nanoparticles (TiO2) were successfully synthesized via a sonochemical-assisted process using titanium isopropoxide as the titanium sources and calcination process at 300-500 °C. The effect of sonication time and heat treatment temperature on structural and nanostructure properties of the nanoparticles were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscope (SEM) and transmission electron microscope (TEM). The XRD and Raman results indicated that the crystalline of as-sonochemically synthesized TiO2 nanoparticles corresponded to anatase phase of TiO2 after sonication for 30 mim. The high quality crystalline anatase phase and increasing of crystalline size can be obtained after calcinations process.

scholarly journals Study on Microstructure and Properties of a New Warm-Stamped Niobium-Alloyed Steel

Metals ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 765
Author(s):  
Peng Tian ◽  
Wen Liang ◽  
Zhennan Cui ◽  
Guoming Zhu ◽  
Yonglin Kang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Heating Temperature ◽  
Mechanical Tests ◽  
Alloyed Steel ◽  
X Ray Diffraction ◽  
Forming Process ◽  
Soaking Time ◽  
Transmission Electron ◽  
Decarburized Layer ◽  
Optimal Heating

The warm stamping technology is a promising technology to meet the needs of car weight reduction and energy conservation. In order to compare with the mechanical properties of the traditional hot-stamped boron-alloyed steel 22MnB5, a new warm-stamped niobium-alloyed steel 22Mn3SiNb was designed and tested. The optimal heating parameters for warm forming process were explored through mechanical tests, and the process of their microstructure evolution was investigated by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD), etc. The experimental results indicate that the optimal heating parameters for the niobium-alloyed steel 22Mn3SiNb are a heating temperature of 800 °C and a soaking time of 5 min. Compared to the hot-stamped boron-alloyed steel 22MnB5 under their respective optimal heating parameters, the properties and microstructure characteristics of 22Mn3SiNb are greatly improved, and nearly no decarburized layer is found on the surface of the niobium-alloyed steel 22Mn3SiNb. In addition, the addition of Nb produces the effects of grain refinement and precipitation strengthening due to the introduction of plenty of nano-precipitated particles and dislocations. In the end, it can be predicted that the new warm-stamped niobium-alloyed steel will replace the conventional hot-stamped boron-alloyed steel.

scholarly journals Formation of ZnO/Zn0.5Cd0.5Se Alloy Quantum Dots in the Presence of High Oleylamine Contents

Nanomaterials ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 999
Author(s):  
Yi-An Chen ◽  
Kuo-Hsien Chou ◽  
Yi-Yang Kuo ◽  
Cheng-Ye Wu ◽  
Po-Wen Hsiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Quantum Dots ◽  
Particle Size ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Transmission Electron ◽  
Average Size ◽  
Alloy Quantum Dots ◽  
First Time

To the best of our knowledge, this report presents, for the first time, the schematic of the possible chemical reaction for a one-pot synthesis of Zn0.5Cd0.5Se alloy quantum dots (QDs) in the presence of low/high oleylamine (OLA) contents. For high OLA contents, high-resolution transmission electron microscopy (HRTEM) results showed that the average size of Zn0.5Cd0.5Se increases significantly from 4 to 9 nm with an increasing OLA content from 4 to 10 mL. First, [Zn(OAc)2]–OLA complex can be formed by a reaction between Zn(OAc)2 and OLA. Then, Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) data confirmed that ZnO is formed by thermal decomposition of the [Zn(OAc)2]–OLA complex. The results indicated that ZnO grew on the Zn0.5Cd0.5Se surface, thus increasing the particle size. For low OLA contents, HRTEM images were used to estimate the average sizes of the Zn0.5Cd0.5Se alloy QDs, which were approximately 8, 6, and 4 nm with OLA loadings of 0, 2, and 4 mL, respectively. We found that Zn(OAc)2 and OLA could form a [Zn(OAc)2]–OLA complex, which inhibited the growth of the Zn0.5Cd0.5Se alloy QDs, due to the decreasing reaction between Zn(oleic acid)2 and Se2−, which led to a decrease in particle size.

Shape control of silver selenide nanoparticles using green capping molecules

2017 ◽  
Vol 6 (2) ◽  
Author(s):  
Nokwethemba Precious Sibiya ◽  
Makwena Justice Moloto
Keyword(s):  
Shape Control ◽  
Orthorhombic Phase ◽  
Silver Selenide ◽  
Capping Agent ◽  
X Ray Diffraction ◽  
Synthesis Of Nanoparticles ◽  
Size And Shape ◽  
Transmission Electron ◽  
Different Shapes ◽  
Average Size

AbstractEmploying a capping agent during the synthesis of nanoparticles has been reported to play a role in controlling size and shape of the nanoparticles. Due to this reason, this study reports the synthesis of silver selenide nanoparticles using different environmentally friendly capping agents (green tea, glucose, ascorbic acid and chitosan) in order to investigate their effect on the size and shape of the nanoparticles. Transmission electron microscopy (TEM) results showed that the nanoparticles have different shapes (rods, spheres and cubes) with an average size of 8–96 nm depending on the capping agent used. Fourier transformer infrared (FTIR) spectroscopy confirmed that the capping of nanoparticles was successful, while X-ray diffraction (XRD) showed that the nanoparticles have an orthorhombic phase.

Synthesis and Characterization of Cu2FeSnS4 Semiconductor Nanocrystals with Zincblende Structure

2012 ◽  
Vol 512-515 ◽  
pp. 2019-2022 ◽  
Author(s):  
Xiao Lu Liang ◽  
Xian Hua Wei
Keyword(s):  
Random Distribution ◽  
Semiconductor Nanocrystals ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Nir Absorption ◽  
Average Size

Cu2FeSnS4semiconductor nanocrystals with zincblende structure have been successfully synthesized by a hot-injection approach. Cu+, Fe2+, and Sn4+cations have a random distribution in the zincblende unit cell, and the occupancy possibilities are 1/2, 1/4 and 1/4, respectively. Those nanocrystals were characterized by means of X-ray diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), energy dispersive spectroscopy (EDS), and UV-Vis-NIR absorption spectroscopy. The Cu2FeSnS4 nanocrystals have an average size of 7.5 nm and a band gap of 0.92 eV.

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