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Mechanism of Quenching of Superconductivity in the YBa2Cu3O7-Delta System on Substitution of Zn For Cu

Garg, K. B.; Gaur, S. K.; Singhal, R. K.; Pal, P.; Sekhar, B. R.; Nordblad, P. and Carlson, Stefan LU (2010) In International Journal of Modern Physics B 24(14). p.2135-2148
Abstract
Substituting Zn for Cu is known to rapidly quench superconductivity in the doped perovskites but the mechanism behind it is still not clearly understood. Single phase YBa2(Cu1-xZnx)(3)O7-delta (x=0.0 to 0.06) samples were synthesized and characterized using XRD, wet titration, resistivity, and ac susceptibility. Angle-integrated Valence Band Photo emission and Zn K-edge XAFS results clearly show that their oxygen stoichiometry (delta) changes on Zn substitution, there by adversely affecting the density of free charge carriers and hence the normal state resistivity and the T-c. However, the observed changes in the two happen to be too large to be accounted for solely on the basis of changes in the oxygen stoichiometry delta. We find that... (More)
Substituting Zn for Cu is known to rapidly quench superconductivity in the doped perovskites but the mechanism behind it is still not clearly understood. Single phase YBa2(Cu1-xZnx)(3)O7-delta (x=0.0 to 0.06) samples were synthesized and characterized using XRD, wet titration, resistivity, and ac susceptibility. Angle-integrated Valence Band Photo emission and Zn K-edge XAFS results clearly show that their oxygen stoichiometry (delta) changes on Zn substitution, there by adversely affecting the density of free charge carriers and hence the normal state resistivity and the T-c. However, the observed changes in the two happen to be too large to be accounted for solely on the basis of changes in the oxygen stoichiometry delta. We find that the Zn cation acts as a strong "impurity" scattering centre in the YBCO lattice and causes local lattice distortion (LLD). It consequently induces local magnetic moment, seen in our dc susceptibility measurements. It is thus a composite of (Delta delta), LLD and possibly also magnetic pair-breaking that is responsible for the rapid quenching of the super conductivity observed with Zn doping in this system. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
magnetic pair-breaking, local lattice distortion, Zn-doping, XAFS, density of states
in
International Journal of Modern Physics B
volume
24
issue
14
pages
2135 - 2148
publisher
World Scientific
external identifiers
  • wos:000279224300005
  • scopus:77954129839
ISSN
0217-9792
DOI
10.1142/S0217979210055342
language
English
LU publication?
yes
id
5c0d529e-59f9-463f-b872-c65ed71146c6 (old id 1630150)
date added to LUP
2010-07-23 12:37:31
date last changed
2018-05-29 10:18:28
@article{5c0d529e-59f9-463f-b872-c65ed71146c6,
  abstract     = {Substituting Zn for Cu is known to rapidly quench superconductivity in the doped perovskites but the mechanism behind it is still not clearly understood. Single phase YBa2(Cu1-xZnx)(3)O7-delta (x=0.0 to 0.06) samples were synthesized and characterized using XRD, wet titration, resistivity, and ac susceptibility. Angle-integrated Valence Band Photo emission and Zn K-edge XAFS results clearly show that their oxygen stoichiometry (delta) changes on Zn substitution, there by adversely affecting the density of free charge carriers and hence the normal state resistivity and the T-c. However, the observed changes in the two happen to be too large to be accounted for solely on the basis of changes in the oxygen stoichiometry delta. We find that the Zn cation acts as a strong "impurity" scattering centre in the YBCO lattice and causes local lattice distortion (LLD). It consequently induces local magnetic moment, seen in our dc susceptibility measurements. It is thus a composite of (Delta delta), LLD and possibly also magnetic pair-breaking that is responsible for the rapid quenching of the super conductivity observed with Zn doping in this system.},
  author       = {Garg, K. B. and Gaur, S. K. and Singhal, R. K. and Pal, P. and Sekhar, B. R. and Nordblad, P. and Carlson, Stefan},
  issn         = {0217-9792},
  keyword      = {magnetic pair-breaking,local lattice distortion,Zn-doping,XAFS,density of states},
  language     = {eng},
  number       = {14},
  pages        = {2135--2148},
  publisher    = {World Scientific},
  series       = {International Journal of Modern Physics B},
  title        = {Mechanism of Quenching of Superconductivity in the YBa2Cu3O7-Delta System on Substitution of Zn For Cu},
  url          = {http://dx.doi.org/10.1142/S0217979210055342},
  volume       = {24},
  year         = {2010},
}