scholarly journals Fifty years of Rietveld refinement: Methodology and guidelines in superconductors and functional magnetic nanoadsorbents

2021 ◽  
Vol 24 (3) ◽  
pp. 39-48
Author(s):  
Diego Alberto Flores Cano ◽  
Anais Roxana Chino Quispe ◽  
Renzo Rueda Vellasmin ◽  
Joao Andre Ocampo Anticona ◽  
Juan Carlos González ◽  
...  

The Rietveld refinement method has taken high relevance since its creation. Nowadays, it is an useful tool in many fields of industry, materials science, and technology. For these reasons, it becomes a need for scientists and engineers whom pretend to use it for proper analysis of their materials. However, the initiation in the method can be slow, taking into account the accelerated rhythm of the research and economic demands. Thus, this work is an intend to fulfill this hole, providing the basic foundations and methodology of the Rietveld refinement in a brief way, this along with the results of its application in superconducting samples of Yttrium Barium Copper Oxide and magnesium diboride, and functional magnetic nanoadsorbents of maghemite and a multiphasic composite (iron oxide, hydroxyapatite and secondary phases). In the process, an in-detail protocol was designed and provided. It was concluded that the samples were successfully refined and that this work represents a fast introduction to the Rietveld method for which beginners can obtain good results while making correct interpretations ofthe whole refinement process.

1992 ◽  
Vol 269 ◽  
Author(s):  
R. B. James ◽  
R. A. Alvarez ◽  
A. K. Stamper ◽  
X. J. Bao ◽  
T. E. Schlesinger ◽  
...  

ABSTRACTWe have used 2.0-μsec microwave pulses at a frequency of 2.856 GHz to rapidly heat thin amorphous yttrium-barium-copper-oxide (YBCO) films deposited onto silicon substrates. The samples were irradiated inside a WR-284 waveguide by single-pass TE10 pulses in a traveling wave geometry. X-ray diffractometry studies show that an amorphous-to-crystalline phase transition occurs for incident pulse powers exceeding about 6 MW, in which case the amorphous YBCO layer is converted to Y2BaCuO5. Microscopy of the irradiated film reveals that the phase transition is brought about by melting of the YBCO precursor film and crystallization of the molten layer upon solidification. Time-resolved in situ experiments of the microwave reflectivity (R) and transmissivity (T) show that there is an abrupt change in R for microwave pulse powers exceeding the melt threshold, so that measurements of R and T can be used to monitor the onset of surface melting.


1989 ◽  
Vol 42 (4) ◽  
pp. 401
Author(s):  
GJ SIoggett ◽  
lK Harvey ◽  
L Wieczorek ◽  
RE Binks ◽  
R Driver

Two experiments pertaining to the effects of intergranular flux penetration in high-Tc yttrium-barium-copper oxide (YBCO) SQUIDs are described. The first is a direct measurement of the flux noise of bulk YBCO exposed to the earth's magnetic field, and the second involves the fabrication and testing of break junction d.c. SQUIDs. Implications of a number of undesirable effects seen in these experiments are discussed.


ChemInform ◽  
1990 ◽  
Vol 21 (3) ◽  
Author(s):  
H. YASUOKA ◽  
T. SHIMIZU ◽  
T. IMAI ◽  
S. SASAKI ◽  
Y. UEDA ◽  
...  

1988 ◽  
Vol 110 (20) ◽  
pp. 6716-6720 ◽  
Author(s):  
Ruth. Jones ◽  
Peter P. Edwards ◽  
Martin R. Harrison ◽  
Thitinant. Thanyasiri ◽  
Ekkehard. Sinn

2002 ◽  
Vol 8 (S02) ◽  
pp. 1484-1485
Author(s):  
Eric Lifshin ◽  
Michael S. Hatzistergos ◽  
Jodi L. Reeves ◽  
Raynald Gauvin

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