Abstract
We have performed neutron powder diffraction (NPD) experiments on polycrystalline powders with nominal compositions (Ca0.5La 0.5)(Ba1.25La0.75)Cu3O 7-δ, (Ca0.6La0.4)(Ba 1.15La0.85)Cu3O7-δ and (Ca0.8La0.2)(Ba0.95La1.05)Cu 3O7-δ. The diffraction patterns, analysed by the Rietveld method, show that all samples consist mainly of a tetragonal Y-123 type phase. Unit cell parameters a and c shorten as the calcium content increases: a = 3.8660(2), 3.8634(3), and 3.8624(5) Å; c = 11.6325(11), 11.6143(14), and 11.5822(20) Å for x-values 0.5, 0.6, and 0.8, respectively. For the x = 0.6 and 0.8 samples the Rietveld refinement of calcium occupancies and EDX analysis suggest that the actual composition is closer to x ≈ 0.5. However, since the lattice parameters do change, it is also suggested that at these higher doping levels calcium does enter the Y-site to a larger extent than for the x = 0.5 composition. This is also in accordance with previously reported values for the Tc, which decreases slighty as x changes from 0.5 to 0.6 and has a pronounced change from 80 K to 73 K for x = 0.6 and 0.8, respectively.
| Original language | English |
|---|---|
| Pages (from-to) | 361-364 |
| Number of pages | 4 |
| Journal | Materials Science Forum |
| Volume | 443-444 |
| Publication status | Published - 2004 |
| Externally published | Yes |
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Keywords
- High-T Superconductor
- Neutron Powder Diffraction
- Rietveld Analysis
ASJC Scopus subject areas
- Materials Science(all)
Cite this
The Effect of Varying Ca-Content on the Structure of High-TC Superconductor (CaxLa1-x)(Ba1.75-xLa 0.25+x)Cu3O7-δ (x = 0.5, 0.6, and 0.8) Studied by Neutron Powder Diffraction. / Sato, Yasushi; Valkeapää, Markus; Petrykin, Valery; Osada, Minoru; Eriksson, Sten; Kakihana, Masato; Rundlöf, Håkan.
In: Materials Science Forum, Vol. 443-444, 2004, p. 361-364.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - The Effect of Varying Ca-Content on the Structure of High-TC Superconductor (CaxLa1-x)(Ba1.75-xLa 0.25+x)Cu3O7-δ (x = 0.5, 0.6, and 0.8) Studied by Neutron Powder Diffraction
AU - Sato, Yasushi
AU - Valkeapää, Markus
AU - Petrykin, Valery
AU - Osada, Minoru
AU - Eriksson, Sten
AU - Kakihana, Masato
AU - Rundlöf, Håkan
PY - 2004
Y1 - 2004
N2 - We have performed neutron powder diffraction (NPD) experiments on polycrystalline powders with nominal compositions (Ca0.5La 0.5)(Ba1.25La0.75)Cu3O 7-δ, (Ca0.6La0.4)(Ba 1.15La0.85)Cu3O7-δ and (Ca0.8La0.2)(Ba0.95La1.05)Cu 3O7-δ. The diffraction patterns, analysed by the Rietveld method, show that all samples consist mainly of a tetragonal Y-123 type phase. Unit cell parameters a and c shorten as the calcium content increases: a = 3.8660(2), 3.8634(3), and 3.8624(5) Å; c = 11.6325(11), 11.6143(14), and 11.5822(20) Å for x-values 0.5, 0.6, and 0.8, respectively. For the x = 0.6 and 0.8 samples the Rietveld refinement of calcium occupancies and EDX analysis suggest that the actual composition is closer to x ≈ 0.5. However, since the lattice parameters do change, it is also suggested that at these higher doping levels calcium does enter the Y-site to a larger extent than for the x = 0.5 composition. This is also in accordance with previously reported values for the Tc, which decreases slighty as x changes from 0.5 to 0.6 and has a pronounced change from 80 K to 73 K for x = 0.6 and 0.8, respectively.
AB - We have performed neutron powder diffraction (NPD) experiments on polycrystalline powders with nominal compositions (Ca0.5La 0.5)(Ba1.25La0.75)Cu3O 7-δ, (Ca0.6La0.4)(Ba 1.15La0.85)Cu3O7-δ and (Ca0.8La0.2)(Ba0.95La1.05)Cu 3O7-δ. The diffraction patterns, analysed by the Rietveld method, show that all samples consist mainly of a tetragonal Y-123 type phase. Unit cell parameters a and c shorten as the calcium content increases: a = 3.8660(2), 3.8634(3), and 3.8624(5) Å; c = 11.6325(11), 11.6143(14), and 11.5822(20) Å for x-values 0.5, 0.6, and 0.8, respectively. For the x = 0.6 and 0.8 samples the Rietveld refinement of calcium occupancies and EDX analysis suggest that the actual composition is closer to x ≈ 0.5. However, since the lattice parameters do change, it is also suggested that at these higher doping levels calcium does enter the Y-site to a larger extent than for the x = 0.5 composition. This is also in accordance with previously reported values for the Tc, which decreases slighty as x changes from 0.5 to 0.6 and has a pronounced change from 80 K to 73 K for x = 0.6 and 0.8, respectively.
KW - High-T Superconductor
KW - Neutron Powder Diffraction
KW - Rietveld Analysis
UR - http://www.scopus.com/inward/record.url?scp=17544392103&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=17544392103&partnerID=8YFLogxK
M3 - Article
AN - SCOPUS:17544392103
VL - 443-444
SP - 361
EP - 364
JO - Materials Science Forum
JF - Materials Science Forum
SN - 0255-5476
ER -