Role of Sm3+ Addition on Humidity Sensing of Nanocrystallite Mg-Cd Ferrites

2013 ◽  
Vol 645 ◽  
pp. 160-163 ◽  
Author(s):  
Gadkari B. Ashok ◽  
Shinde J. Tukaram ◽  
Vasambekar N. Pramod

Nanocrystallite powders of 5 wt% Sm3+ added Mg-Cd ferrite samples were prepared by oxalate co-precipitation method. XRD, SEM and FT-IR techniques were used for characterization of the samples. The XRD reveals cubic spinel nature with secondary phase (SmFeO3). The crystallite size lies in the range of 28.69 to 32.66 nm. All the Sm3+ ions added samples are humidity sensitive at low humidity range 40 to70 %RH. The electrical resistivity of Sm3+ ions added samples decreased by four orders of magnitude, when %RH increased from 40%RH to 90 %RH. The response and recovery time of all the samples are 160-290 sec. The shorter response time was observed for Sm3+ added Cd ferrite sensor.

2016 ◽  
Vol 25 (6) ◽  
pp. 096369351602500 ◽  
Author(s):  
Ruimin Fu ◽  
Mingfu Zhu

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4 magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4 in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.


2011 ◽  
Vol 284-286 ◽  
pp. 839-843 ◽  
Author(s):  
Li Li Wang ◽  
Jin Chen ◽  
Guang Cheng Yang ◽  
Fu De Nie

A carbonate precursor with high sintering activity was prepared by co-precipitation method under ultrasonic radiation. This precursor precipitant completely transformed to pure YAG phase after being calcined at 900 °C for 4 h. The properties of YAG nanopowders obtained under different synthetic process were studied by XRD, TG-DSC, FT-IR and SEM. The results show that the ultrasonic radiation can fine the precursor and reduce its agglomeration. YAG nanopowders with an average particle size of about 60 nm were obtained and particles were sphere-shaped with good dispersity.


2014 ◽  
Vol 574 ◽  
pp. 338-341
Author(s):  
Zi Fen Zhao ◽  
Hui Ping Shao ◽  
Sen Sun

In this paper, the oil-based magnetic fluid was prepared by chemical co-precipitation method and sodium oleate was the surfactant. The effect of different pH on the characterization of magnetic fluid was studied. The characterization was detected by Fourier Transform Infrared spectroscopy (FT-IR), Transmission Electron Microscope (TEM) and Vibrating Sample Magnetometer (VSM). The results show that the nanoparticles were coated successfully by sodium oleate at pH=5. And the saturation magnetization of Fe3O4 magnetic nanoparticles is 58.0 emu/g, the saturation magnetization of magnetic fluid prepared is 20.2 emu/g, and the Fe3O4 particles are dispersed well. Although the Fe3O4 magnetic particles coated by sodium oleate at pH = 10.5 has a higher saturation magnetization (67.8 emu/g), but the magnetic fluid is less stable and has an obvious settlement phenomenon.


2001 ◽  
Vol 15 (17) ◽  
pp. 2387-2407 ◽  
Author(s):  
ABDUL NAYEEM ◽  
K. YADAIAH ◽  
G. VAJRALINGAM ◽  
P. MAHESH ◽  
M. NAGABHOOSHANAM

Copper doped Cd 1-x Zn x S compounds were prepared by controlled precipitation method with 0≤x≤1. The samples were characterized by X-ray, chemical analysis, optical absorption, and SEM studies. The X-ray studies have indicated that the compounds have polycrystalline nature with mixed Hexagonal and Cubic structure of CdS with x=0–0.6, the structure changed to a prominent cubic structure of ZnS with x>0.6. Optical studies have shown that the grain size increased with x varying from 0–0.2 and then it decreased. It was also observed that the optical energy gap decreased with x till x ⋍ 0.2, attained a minimum with x=0.2 and then it increased gradually. The values of E g obtained for CdS and ZnS were 2.21 eV and 2.53 eV. The chemical homogeneity of the samples was also observed from the EDAX and noted that the sulfur and copper contents remained almost the same, and the decrease in Cd and increase in Zn atoms occurred systematically. The results were explained on the basis of different phases formed and the role of copper impurity.


2020 ◽  
Vol 3 (1) ◽  
pp. 30-33
Author(s):  
Muthulakshmi M ◽  
Madhumitha G

Nanotechnology is a field of applied science focused on design, synthesis and characterization of nanomaterials. The nickel and magnesium have improved their applications in transparent electrodes and nano electronics. In addition, magnesium oxide has moisture resistance and high melting point properties. In the present work has been carried out in the development of green crystalline powder of nickel doped magnesium oxide nanoparticles by Co-precipitation method, from the mixture of nickel chloride and magnesium chloride with KOH as solvent. From the XRD results, crystalline size of the particle can be observed. Spherical structure of Ni doped MgO nanoparticles were indicated by SEM results and powdered composition of samples were obtained from FTIR. EDAX represents the peak composition of the nanoparticle. The above analytical techniques have confirmed that the Ni doped MgO nanoparticles obtained from the mixture of NiCl2 and MgCl2.


MRS Advances ◽  
2017 ◽  
Vol 2 (64) ◽  
pp. 4025-4030 ◽  
Author(s):  
T. Kryshtab ◽  
H. A. Calderon ◽  
A. Kryvko

ABSTRACTThe microstructure of Ni-Mg-Al mixed oxides obtained by thermal decomposition of hydrotalcite-like compounds synthesized by a co-precipitation method has been studied by using X-ray diffraction (XRD) and atomic resolution transmission electron microscopy (TEM). XRD patterns revealed the formation of NixMg1-xO (x=0÷1), α-Al2O3 and traces of MgAl2O4 and NiAl2O4 phases. The peaks profile analysis indicated a small grain size, microdeformations and partial overlapping of peaks due to phases with different, but similar interplanar spacings. The microdeformations point out the presence of dislocations and the peaks shift associated with the presence of excess vacancies. The use of atomic resolution TEM made it possible to identify the phases, directly observe dislocations and demonstrate the vacancies excess. Atomic resolution TEM is achieved by applying an Exit Wave Reconstruction procedure with 40 low dose images taken at different defocus. The current results suggest that vacancies of metals are predominant in MgO (NiO) crystals and that vacancies of Oxygen are predominant in Al2O3 crystals.


2017 ◽  
Vol 43 (15) ◽  
pp. 12120-12125 ◽  
Author(s):  
S.A.N.H. Lavasani ◽  
O. Mirzaee ◽  
H. Shokrollahi ◽  
A.K. Moghadam ◽  
M. Salami

2015 ◽  
Vol 645-646 ◽  
pp. 1339-1344 ◽  
Author(s):  
Yan Ting Yin ◽  
Qing Hua Chen ◽  
Ting Ting Yan ◽  
Qing Hua Chen

The objective of this study was to develop a novel silica modified large-sized hydroxyapatite whiskers with improved properties for use in bone repair applications. Large-sized whiskers with a mean length of 250μm were obtained by a hydrothermal co-precipitation method at 150°C, 7.5Mpa in high-pressure reactor. Silica modified hydroxyapatite whiskers were prepared by dissolving TEOS in ethanol solution, then sintering with hydroxyapatite. The compositional and morphological properties of prepared whiskers were studied by means of x-ray diffraction (XRD), Fouier transform infrared (FT-IR), scanning electron microscopy (SEM). The results indicated the evidence of nanosilicon dioxide particles on the surface of HAP whiskers. The size of nanosilicon dioxide particles depends on dropping and stirring rate. Hence, this new type of silica modified large-sized hydroxyapatite whiskers is a valuable candidate for biomedical applications.Key words: hydroxyapatite, hydrothermal co-precipitation, surface modified, whiskers


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