scholarly journals Synthesis of MSn(OH)6 (where M = Mg, Ca, Zn, Mn, or Cu) materials at room temperature

2010 ◽  
Vol 8 (1) ◽  
pp. 65-69 ◽  
Author(s):  
Jonathan Kramer ◽  
Brandon Kelly ◽  
Venkatesan Manivannan

AbstractApplying a metathesis approach (MCl2·xH2O+Na2SnO3·xH2O→MSn(OH)6+NaCl+xH2O), Schoenfliesite-type materials with general formula MSn(OH)6 (where M=Ca, Cu, Mg, Mn or Zn) were synthesized at room-temperature. The high lattice-energy of the by-product alkali halide NaCl drives the reaction in the forward direction leading to the formation of the desired materials. The materials synthesized were characterized by powder X-ray diffraction (XRD) and scanning electron microscopy (SEM) to elucidate structural and micro structural features.


2019 ◽  
Vol 33 (03) ◽  
pp. 1950027 ◽  
Author(s):  
Jiaxiang Chen ◽  
Xiaopeng Jia ◽  
Yuewen Zhang ◽  
Haiqiang Liu ◽  
Baomin Liu ◽  
...  

The polycrystalline skutterudite [Formula: see text] were successfully synthesized from 1.5 GPa to 3.5 GPa by the high pressure and high temperature (HPHT) method. Negative Seebeck coefficient confirmed the n-type conductivity of all samples. The phase compositions of samples were investigated by X-ray diffraction (XRD) and the microstructures were observed by scanning electron microscopy (SEM). It was found that the grains appeared smaller and the grain boundaries became more abundant when pressures were higher. We measured the electrical properties from room temperature to 723 K. Both the electrical resistivity and absolute value of Seebeck coefficient increase with the increasing synthetic pressure. At 723 K, the maximum power factor of [Formula: see text] was obtained for the sample synthesized under 3 GPa. The maximum ZT value of 0.61 was reached by [Formula: see text] synthesized under 3 GPa and measured at 723 K.



2017 ◽  
Vol 23 (S1) ◽  
pp. 934-935
Author(s):  
R. Rodriguez-Mijangos ◽  
O. Hernández-Negrete ◽  
R. C. Carrillo-Torres ◽  
F. J. Carrillo-Pesqueira ◽  
M. E. Alvarez-Ramos ◽  
...  


2006 ◽  
Vol 11-12 ◽  
pp. 677-680 ◽  
Author(s):  
Gunawan Hadiko ◽  
Yong Sheng Han ◽  
Masayoshi Fuji ◽  
Minoru Takahashi

Hollow calcium carbonate (CaCO3) particles were synthesized by bubbling CO2 in the solution of calcium chloride (CaCl2) with the presence of ammonia at room temperature. Hollow calcium carbonate is a potential component to be used as pharmaceuticals, agrochemicals, and catalysis. This paper investigated the effect of additive on the hollow structure. In this study was used vanadate ion as additive agent. Physical characteristics of precipitate were evaluated using scanning electron microscopy (SEM) and X-ray diffraction (XRD).



2009 ◽  
Vol 23 (06n07) ◽  
pp. 1548-1552
Author(s):  
X. K. ZHU ◽  
K. Y. ZHAO ◽  
C. J. LI ◽  
J. M. TAO ◽  
T. L. CHAN ◽  
...  

The purpose of experiment was to produce bulk nanocrystalline Zn by mechanical attrition. The bulk nanocrystalline Zn produced by mechanical attrition was studied. The microstructural evolution during cryomilling and subsequent room temperature milling was characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD). In this paper, Nanocrystalline Zn was produced by insitu consolidation of Zn elemental powder using mechanical attrition at liquid nitrogen and room temperature. For the samples studied, the longest elongation of 65% and highest stress of 200 MPa is obtained in nanocrystalline Zn during tensile testing at the condition of strain rate (10-3 sec-1) and 20°C which is equal to 0.43 Tm (Tm is the melting temperature of pure Zn ).



2010 ◽  
Vol 8 (2) ◽  
pp. 434-439 ◽  
Author(s):  
Junhao Zhang ◽  
Ling Yang ◽  
Xiaofang Cheng ◽  
Jinmeng Zhang ◽  
Fucai Li

AbstractHierarchical nickel microwires with nanothorns were fabricated through a reduction of nickelous salt with hydrazine in diethanolamine. The product was characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDS). The growth mechanism of the nickel microwires with nanothorns is proposed, based on the evolution of the structures and morphologies, which could be ascribed to the cooperative effect of the complexant of diethanolamine and inherent magnetic interactions. Magnetic properties of the product were measured at room temperature and compared with other shaped counterparts.



2013 ◽  
Vol 745-746 ◽  
pp. 507-511
Author(s):  
Jun Chen ◽  
Yue Zhang

A series of Al2O3-SiO2 ceramic cores with titanium sol sintered at 1350, 1450, 1500 and 1550for 2h, respectively, were prepared, and the phase and microstructure were characterized by X-ray Diffraction and Scanning Electron Microscopy. The influence of titanium sol on the phase transformation, shrinkage rate and flexural strength at room temperature has been investigated. The mullite phase formation temperature decreased by at least 150with the addition of 1wt% to 5wt% TiO2. Additionally, the titania additive promoted the combination of Al2O3 and SiO2, producing mullite phase which reduced the shrinkage and improved the flexural strength.



2009 ◽  
Vol 12 (3) ◽  
pp. 77-84
Author(s):  
Thao Tien Nguyen ◽  
Ngoan Thi Nguyen ◽  
Long Van Dang

All TiO2/SiO2 samples were prepared by the impregnation of Ti(i-PrO)4 in isopropanol at room temperature followed drying and calcination. The solids were characterized by several techniques including X- ray diffraction (XRD), IR spectroscopy, Scanning Electron Microscopy (SEM). No reflection lines of TiO2 are detected at a low content of TiO2 (< 7%), but are more visible at a higher concentration. The catalysts are tested in the liquid oxidation of styrene under mild conditions, producing mainly benzaldehyde. The effects of variables on the catalytic activity are also investigated.



Author(s):  
Yu. S. Haiduk ◽  
A. A. Khort ◽  
M. A. Mokhovikov ◽  
A. A. Savitsky

Nanocrystalline tungsten oxide (WO3), indium oxide (In2O3), cobalt oxide (Co3O4) and mixed composites with different WO3—In2O3 and WO3—Co3O4 ratios were obtained by the sol-gel method after calcination of xerogels at 400—600 °C. The morphology, phase composition, and structural features of the materials obtained were studied by X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The increase in the gas sensitivity of the joint composition compared to the initial oxides can be explained by a decrease in the crystallite size and an increase in the specific surface, as well as by the dependence of the surface state of the grains on the composition. The highest sensory response to nitrogen dioxide in both compositions lies in the range of 130—150 °C, and to carbon monoxide, above 230 °C. Low-power planar nitrogen dioxide sensors with a sensitivity of << 1 ppm and power consumption ≤ 85 mW were produced.



2019 ◽  
Vol 24 (4) ◽  
pp. 69
Author(s):  
Mohammed Mustafa Rashid1 ◽  
Sabah J. Fathi2 ◽  
Rafea A. Munef ◽  
Bilal Omer Ahmed1

The nanocomposites ferrites (BaFe12O19/Ni0.3Cu0.2Zn0.5Al­0.5Fe1.5O4) with (x=10,25,50,75,90%) were prepared by sol-gel auto combustion. The micro-structural features of the samples were studied using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The results were compared which show that the grain size of the nano composites which prepared by sol-gel auto combustion about (25-46) nm.   http://dx.doi.org/10.25130/tjps.24.2019.075  



1991 ◽  
Vol 226 ◽  
Author(s):  
H.S. Koo ◽  
T.L. Kuo ◽  
D.H. Kuo ◽  
R.J. Lin ◽  
W.H. Lee ◽  
...  

AbstractSuperconducting TI-Ba-Ca-Cu-O(TBCCO) films with zero resistance temperatures above 100K have been prepared on (001)MgO single-crystal substrates by the combination techniques of spray pyrolysis and Tl-diffusion. The as-sprayed Ba-Ca-Cu-O films and the sintered TBCCO superconducting bulks were wrapped in Au foil and heated in oxygen at temperatures ranging from 890 to 920°C and cooled to room temperature by furnace cooling. Highly c-axis oriented superconducting films were obtained and their average thicknesses were about 5-10 μm. The characteristics of TBCCO films by X-ray diffraction, scanning electron microscopy and electrical property are discussed.



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