Infiltration growth processing of bulk mixed REBa2Cu3O7-x superconductors: nano-metal oxides and rare earth elements effects on microstructural properties

Author(s):  
Pavan Kumar Naik S ◽  
Nagaveni K ◽  
Swarup Raju P. M. ◽  
Muralidhar M ◽  
Koblischka M.R. ◽  
...  
1993 ◽  
Vol 27 (9) ◽  
pp. 1796-1802 ◽  
Author(s):  
Dirk Koeppenkastrop ◽  
Eric H. De Carlo

MRS Advances ◽  
2018 ◽  
Vol 3 (1-2) ◽  
pp. 121-126
Author(s):  
Patsy Y. Arquieta Guillén ◽  
Alena Borisovna Kharissova ◽  
Beatriz Ortega García ◽  
Oxana V. Kharissova

ABSTRACTNowadays, carbon nanotubes have a lot of applications in daily life, being applied in the fabrication of cellphones, computers, nanotransistors, among many others. Currently, their new applications in biotechnology area are in research, in particular in order to find new biosensors with fluorescent properties applying on the basis of multi-wall carbon nanotubes (MWCNTs). In this work, the obtaining of carbon nanoparticles having fluorescent properties via spray pyrolysis is presented. Synthesis, properties, structural peculiarities, and applications of nanobuds and related nanostructures are discussed. MWCNTs, decorated with strontium aluminate SrAl12O19 and doped with rare-earth elements, were synthetized from distinct organic precursors and the corresponding metal oxides. The metal oxides used were Samarium (Sm), Europium (Eu), Neodymium (Nd), Lanthanum (La), Cerium (Ce) and some their combinations.The synthesis was carried out on the surface of optical fibres to obtain a uniform growth of forest-like MWCNTs, adding to metal oxide nanoparticles to their surface. The preparation of composites was carried out by spray pyrolysis techniques in dry nitrogen atmosphere in the temperature range from 780 to 850°C. The formed products were characterized by Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), FTIR spectroscopy, Raman spectroscopy and UV/visible spectroscopies. The analysis of the obtained data shows that the deposited nanoparticles are in the range of size 20-60 nm being uniformly distributed on the surface of MWCNTs. The samples, obtained at different temperatures and with doping metal oxides added to SrAl12O19, show different fluorescence behavior. The best results were observed with lanthanum oxide as a dopant. Possible applications as persistently luminescent phosphors for the formed MWCNTs-supported luminescent materials are proposed.


1999 ◽  
Vol 556 ◽  
Author(s):  
W. L. Gong ◽  
W. Lutze ◽  
R. C. Ewing

AbstractWe synthesized a ceramic containing simulated excess weapons plutonium waste in solidsolution with zirconia (ZrO2)ss. ZrO2 has a large solubility for other metal oxides. More thantwenty binary systems AxOy- ZrO2 have been reported in the literature, including PuG2, rare earth elements, and oxides of metals contained in weapons plutonium wastes. We show that significant amounts of gadolinium (neutron absorber) and yttrium (stabilizer of the cubic modification) can be dissolved in ZrO2, together with plutonium (simulated by Th4+, Ce4+, or U4+) and impurities (e.g., Ca Mg, Fe, Si). Sol-gel and powder methods were applied to make homogeneous, single phase zirconia solid solutions. Pu waste impurities were completely dissolved in the solid solutions. In contrast to other phases, e.g., zirconolite and pyrochlore, yttrium stabilized cubic zirconia does not undergo amorphization upon irradiation.


2020 ◽  
Vol 22 (13) ◽  
pp. 4364-4375 ◽  
Author(s):  
Igor Huskić ◽  
Mihails Arhangelskis ◽  
Tomislav Friščić

Solvent-free accelerated ageing converts metal oxides into metal oxalate frameworks, enabling simple separation of scandium from other rare earth elements.


1962 ◽  
Vol 18 (4) ◽  
pp. 1127-1153
Author(s):  
V FASSEL ◽  
R CURRY ◽  
R KNISELEY

Sign in / Sign up

Export Citation Format

Share Document