Hostname: page-component-848d4c4894-m9kch Total loading time: 0 Render date: 2024-05-07T05:16:11.703Z Has data issue: false hasContentIssue false

Synthesis, Characterization and Ageing of MgB2

Published online by Cambridge University Press:  18 March 2011

A. Serquis
Affiliation:
Superconductivity Technology Center, MS K763
R. Schulze
Affiliation:
Materials Technology Metallurgy Group, MS G755
Y. T. Zhu
Affiliation:
Superconductivity Technology Center, MS K763
J. Y. Coulter
Affiliation:
Superconductivity Technology Center, MS K763
D. E. Peterson
Affiliation:
Superconductivity Technology Center, MS K763
N. O. Moreno
Affiliation:
Condensed Matter and Thermal Physics, MS K764Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87544, USA
P. G. Pagliuso
Affiliation:
Condensed Matter and Thermal Physics, MS K764Materials Science and Technology Division, Los Alamos National Laboratory, Los Alamos, NM 87544, USA
S. S. Indrakanti
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
V. F. Nesterenko
Affiliation:
Department of Mechanical and Aerospace Engineering, University of California, San Diego, La Jolla, CA 92093
F. M. Mueller
Affiliation:
Superconductivity Technology Center, MS K763
Get access

Abstract

We studied the influence of sample preparation and defects in the superconducting properties samples using atomic ratios of Mg:B=1:1 and Mg:B=1:2. Samples were characterized by SEM, and XRD, and the magnetization properties were examined in a SQUID magnetometer. The presence of Mg vacancies was determined by Rietveld analysis. Most of the samples exhibited sharp superconducting transitions with Tcs between 37–39 K.

We found a strong correlation between the crystal strain and the Tc. This strain was related to the presence of Mg vacancies. In addition, results showed that some samples degraded with time when exposed to ambient conditions. In these samples the Tc did not change with time, but the superconducting transition became broader and the Meissner fraction decreased. This effect was only present in samples with poor connectivity between grains and smaller grain sizes. The degradation was related to a surface decomposition as observed by X-ray Photoelectron Spectroscopy. No correlation was found between this effect and the presence of Mg vacancies.

Type
Research Article
Copyright
Copyright © Materials Research Society 2002

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

1 Nagamatsu, J., Nakagawa, N., Muranaka, T., Sentani, Y., and Akimitsu, J., Nature 410, 63 (2001).Google Scholar
2 Zhai, H. Y., Christen, H. M., Zhang, L., Paranthaman, M., Fleming, P. H., and Lowndes, D. H., Supercond. Sci. Technol. 14, 425 (2001).Google Scholar
3 Xue, Y.Y., Meng, R. L., Lorenz, B., Meen, J. M., Sun, Y. Y. and Chu, C. W., condmat/ 0105478 (2001).Google Scholar
4 Bordet, P., Mezouar, M., Nunez-Regueiro, M., Monteverde, M., Nunez-Regueiro, M.D., Rogado, N., Regan, K.A., Hayward, M.A., He, T., Loureiro, S.M., Cava, R.J., cond-mat/0106585 (2001).Google Scholar
5 Buzea, C. and Yamashita, T., Supercond. Sci. Technol. 14, R115 (2001).Google Scholar
6 Cooper, A.S., Corenzwit, E., Longuinotti, L., Matthias, B. T., and Zachariasen, W. H., Proc. Nat. Acad. Sci. 67, 313 (1970).Google Scholar
7 Rogado, N., Hayward, M.A., Regan, K.A., Wang, Yayu, Ong, N.P., Rowell, J.M., and Cava, R.J., cond-mat/0107534 (2001).Google Scholar
8 Zhao, Y.G., Zhang, X.P., Qiao, P.T., Zhang, H.T., Jia, S.L., Cao, B.S., Zhu, M.H., Han, Z.H., Wang, X.L. and Gu, B.L., cond-mat/0105053 (2001).Google Scholar
9 Serquis, A., Zhu, Y.T., Peterson, E.J., Coulter, J.Y., Peterson, D.E., and Mueller, F.M., accepted for publication in Appl. Phys. Lett.Google Scholar
10 Serquis, A., Schulze, R.K., Zhu, Y.T., Peterson, D.E., Indrakanti, S.S., Nesterenko, V.F., and Mueller, F. D., to be submitted to Appl. Phys. Lett.Google Scholar
11 Lawson, A.C., Von Dreele, R.B., GSAS, Generalized Structural Analysis System, Document LAUR 86–748, Los Alamos National Laboratory, Los Alamos, New Mexico, 1993.Google Scholar
12 Young, R. A., The Rietveld Method, edited by International Union of Crystallography (Oxford University Press, Nueva York, 1993), p. 126.Google Scholar
13 Balzar, D., J. Res. Natl. Inst. Stand. Technol. 98, 321 (1993).Google Scholar
14 Schmidt, H., Zasadzinski, J.F., Gray, K.E., Hinks, D.G., Phys. Rev. B 63, 504(R) (2001).Google Scholar