Non Trivial Processes for Obtaining Bi-Based High Tc Superconductors

1998 ◽  
Vol 547 ◽  
Author(s):  
R. Cloots ◽  
M. Ausloos
Keyword(s):  
Magnetic Field ◽  
Growth Process ◽  
Main Axis ◽  
Ac Magnetic Susceptibility ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Melt Texturing ◽  
Scanning Electron

AbstractDysprosium doped Bi-based 2212 ceramics were synthesized by a melt-texturing growth process in a 1.2T magnetic field, applied perpendicularly to the main axis of a cylindrically shaped sample. The materials were characterized by X-ray diffraction, optical and scanning electron microscopy and energy dispersive X-ray analyses. The texturing process was optimized with respect to the sample electrical resistivity and AC magnetic susceptibility.

Synthesis of Magnetic Modified Organobentonite as Adsorbent for Degradation of Orange II

2013 ◽  
Vol 838-841 ◽  
pp. 2306-2309
Author(s):  
Guang Hua Wang ◽  
Kun Chen ◽  
Wen Bing Li ◽  
Dong Wan ◽  
Qin Hu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Reaction Medium ◽  
Precipitation Method ◽  
Basal Spacing ◽  
Orange Ii ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Co Precipitation ◽  
Scanning Electron

Magnetic modified organobentonite (Fe3O4/CTAB–Bent) was synthesized by chemical co-precipitation method in which CTAB–Bent was firstly achieved via ion–exchange.The composite materials have been characterized by powder X–ray diffraction (XRD), Fourier transform infrared spectroscopy (FT–IR) and Scanning electron microscopy (SEM) . The results revealed that basal spacing of bentonite was increased through organic modification and the Fe3O4 particles synthesized which covering the surfaces of bentonite .Compared with natural bentonite, the adsorption capacity of Fe3O4/CTAB–Bent for Orange II was greatly enhanced and can be easily separated from the reaction medium by an external magnetic field after the treatment.

Preparation and Characterization of Tin Doped Tetra-Pod Shaped Zinc Oxide

2005 ◽  
Vol 475-479 ◽  
pp. 1161-1164 ◽  
Author(s):  
Jing Jing Liu ◽  
Zuo Wan Zhou ◽  
Kai Wang ◽  
Yanxia Li
Keyword(s):  
Zinc Oxide ◽  
Growth Process ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Crystal Growth Process ◽  
Zno Crystal ◽  
Weight Proportion ◽  
Scanning Electron

Tin doped tetra-pod shaped ZnO (T-ZnO) were fabricated by equilibrant airflow reaction method. The microstructure of tin doped T-ZnO was characterized by X-ray Diffraction analysis and Scanning Electron Microscope. The results demonstrated that most of tin acted as a catalyst during the ZnO crystal growth process and the others reacted with ZnO to generate Zn2SnO4. Tin had catalytic influences on the morphology of T-ZnO, which promoted predominant growth on the c axis of ZnO crystal at the addition of 15% in weight and advanced the growth on the a axis at higher weight proportion.

SYNTHESIS AND CHARACTERIZATION OF HIGH-Tc SUPERCONDUCTORS IN THE Tl–Ca–Ba–Cu–O SYSTEM

1989 ◽  
Vol 03 (05) ◽  
pp. 733-741
Author(s):  
NAROTTAM P. BANSAL ◽  
D. E. FARRELL
Keyword(s):  
Sintering Temperature ◽  
Resistive Transition ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Resistivity Measurements ◽  
Temperature Time ◽  
Dominant Phase

In an effort to synthesize the high-T c superconducting phase in the thallium system, two nominal compositions, Tl 2 Ca 2 Ba 2 Cu 3 O 10 and Tl 1 Ca 3 Ba 1 Cu 3 O 8.5, have been investigated for superconductivity as a function of the sintering temperature, time, atmosphere, and quench rate. Samples have been characterized by electrical resistivity measurements, X-ray diffraction, and scanning electron microscopy. Samples of starting composition Tl 2 Ca 2 Ba 2 Cu 3 O 10 fired in air at 860–900°C and rapidly quenched showed T c (R = 0) of 96–107 K. In contrast, specimens of starting composition Tl 1 Ca 0 Ba 1 Cu 3 O 8.5 when baked at 900°C and slow cooled in oxygen were superconducting at ≥ 116 K and consisted of Tl 2 Ca 2 Ba 2 Cu 3 O 10+x as the dominant phase. Our results also show that, in contrast to the case of YBa 2 Cu 3 O 7−x, doping with a small concentration of fluorine sharpens the resistive transition and produces large T c increase in thallium-based superconductors.

Volatile Mixed Metal Y-Ba and Ba-Cu Precursors for Mocvd of High Tc Superconductors: A Way to Improve the Transport of Barium ?

1994 ◽  
Vol 346 ◽  
Author(s):  
Liliane G. Hubert-Pfalzgraf ◽  
Florence Labrize ◽  
Herve Guillon ◽  
Patrick Tobaly
Keyword(s):  
Mass Spectrometry ◽  
Thermal Stability ◽  
Pressure Measurements ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Mixed Metal ◽  
Decomposition Experiments ◽  
Vapor Pressure Measurements

ABSTRACTThe fluoroisopropoxide ligand (HFIP) has allowed the synthesis of mixed-metal homoleptic Ba2Y and CuBa alkoxides. However, although these species are all volatile, their poor thermal stability precludes their use as CVD precursors. Their properties have thus been optimized by introduction of 2,2,6,6-tetramethylheptane-3,5-dione (thdH) in the metal coordination sphere. Compounds such as Y2Ba(μ-HFIP)4(thd)4, the first volatile Y-Ba species reported so far, as well as BaCu2(HFIP)4(thd)2 and YCu(HFIP)2(thd)3 have been obtained. These heterometallic ϐdiketonatoalkoxides have been characterized by a variety of techniques including X-ray diffraction, mass spectrometry, vapor pressure measurements and thermogravimetric analysis. Preliminary data on thermal decomposition experiments are given.

VALENCE STATES AND LOCAL ENVIRONMENT OF THALLIUM AND COPPER IONS IN SOME NEW HIGH Tc SUPERCONDUCTORS BY XAS

1989 ◽  
Vol 03 (07) ◽  
pp. 1085-1096 ◽  
Author(s):  
F. STUDER ◽  
R. RETOUX ◽  
C. MARTIN ◽  
C. MICHEL ◽  
B. RAVEAU ◽  
...  
Keyword(s):  
Valence State ◽  
Copper Ions ◽  
Local Environment ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
High Tc ◽  
X Ray ◽  
Valence States ◽  
X Ray Absorption ◽  
Thallium Ions

The valence states of cations inside four high T c thallium superconductors have been investigated by X-ray absorption spectroscopy at thallium LIII , LI and copper K-edges. The thallium ions are observed on LIII and LI edges in the Tl(III) valence state (empty 6s levels) in spite of large Tl-O distances in the (a, b) plane of the structure as deduced from X-ray diffraction. The presence of two types of Tl-O distances have been well established on XANES spectra and the F.T. of EXAFS have shown the presence of two very short Tl-O bonds (2.03 Å). The copper K-edges are characterized by the absence of Cu(I) state (3d10 line).

Solvothermal Synthesis and Electrochemical Properties of Hairball-Like Bismuth Trisulphide Microcrystallines

2011 ◽  
Vol 233-235 ◽  
pp. 2289-2293
Author(s):  
Pin Jiang Li ◽  
Wen Jun Fa ◽  
Yan Ge Zhang ◽  
Bao Jun Huang ◽  
Yi Dong Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solvothermal Synthesis ◽  
Growth Process ◽  
Solvothermal Process ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
One Step ◽  
Scanning Electron

Hairball-like bismuth trisulphide microcrystallines has been successfully prepared via one step solvothermal process and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and high-resolution transmission electron microscopy (HRTEM) techniques. The morphologies of the Bi2S3 microcrystallines were influenced by reaction time, temperature, the mole ratio of the reactants and concentration of starting materials, and the growth process has been proposed. The electrochemical behavior of Bi2S3 was investigated using the cyclic voltammetry.

scholarly journals One-Pot Access to Diverse Functionalized Pyran Annulated Heterocyclic Systems Using SCMNPs@BPy-SO3H as a Novel Magnetic Nanocatalyst

2020 ◽  
Vol 15 (2) ◽  
pp. 348-366 ◽  
Author(s):  
Ke Chen ◽  
Guangzu He ◽  
Qiong Tang ◽  
Qahtan A.Yousif
Keyword(s):  
Magnetic Field ◽  
Reaction Times ◽  
Vibrating Sample Magnetometry ◽  
X Ray Diffraction ◽  
Magnetic Nanocatalyst ◽  
Permanent Magnetic Field ◽  
One Pot ◽  
X Ray ◽  
The One ◽  
Scanning Electron

The SCMNPs@BPy-SO3H catalyst was prepared and characterized using Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Vibrating Sample Magnetometry (VSM), Energy Dispersive X-ray Spectroscopy (EDX), X-ray Diffraction (XRD), and Scanning Electron Microscopy (SEM). Afterwards, its capability was efficiently used to promote the one-pot, three-component synthesis of pyrano[2,3-c]pyrazole and 2-amino-3-cyano-pyrano[3,2-c]chromen-5(4H)-one derivatives. The strategy resulted in the desired products with excellent yields and short reaction times. The SCMNPs@BPy-SO3H catalyst was readily recovered using a permanent magnetic field and it was reused in six runs with a slight decrease in catalytic activity. Copyright © 2020 BCREC Group. All rights reserved 

The Characteristics of Diamond Film Deposited by Magnet-Enhanced Plasma Jet CVD

1996 ◽  
Author(s):  
K. Zhou ◽  
M. Dair ◽  
D. Wang ◽  
P. Han ◽  
B. Feng
Keyword(s):  
Magnetic Field ◽  
Diamond Film ◽  
Polycrystalline Diamond ◽  
Plasma Jet ◽  
Magnetic Effect ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Perfection ◽  
Polycrystalline Diamond Film ◽  
Scanning Electron

Abstract A diameter of 30 mm polycrystalline diamond film has been deposited by magnet-enhanced DC plasma jet CVD. The diamond film was characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy and surface profilograph. Results reveal that under the same depositing parameters, magnetic field can increase purity of diamond film, improve thickness uniformity of diamond film, but no influence on crystal perfection and size of microcrystal of diamond film. A discussion on magnetic effect is presented.

X-ray diffraction peak-broadening analysis of (La-M)2CuO4 high-Tc superconductors

1993 ◽  
Vol 8 (1) ◽  
pp. 2-6 ◽  
Author(s):  
Davor Balzar ◽  
Hassel Ledbetter ◽  
Alexana Roshko
Keyword(s):  
Diffraction Peak ◽  
Line Profiles ◽  
X Ray Diffraction ◽  
High Tc Superconductors ◽  
Fault Probability ◽  
High Tc ◽  
X Ray ◽  
Peak Broadening ◽  
Crystallographic Symmetry ◽  
Stacking Fault Probability

An X-ray diffraction peak-broadening analysis of four oxides is described: La2CuO4 and La1.85M0.15CuO4 (M = Ca,Ba,Sr) high-Tc superconductors. The diffraction line profiles were fitted with a convolution of specimen and instrumental functions, and the specimen peakbroadening angular dependence was analyzed with the Warren-Averbach method. It was found that microstrains and incoherently diffracting domains are highly anisotropic. In the superconductors, stacking-fault probability increases with increasing Tc; microstrain decreases. In La2CuO4, different broadening of (h00) and (0k0) reflections is not caused by stacking faults; it might arise from lower crystallographic symmetry.

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