Hostname: page-component-78c5997874-s2hrs Total loading time: 0 Render date: 2024-11-19T06:36:14.809Z Has data issue: false hasContentIssue false

Diffusional transformation and structural relaxation in Y1Ba2Cu3−xNixO7−z compounds

Published online by Cambridge University Press:  31 January 2011

S.V. Raman
Affiliation:
Department of Physics, Texas Center for Superconductivity, University of Houston, Houston, Texas 77204
Y.Y. Sun
Affiliation:
Department of Physics, Texas Center for Superconductivity, University of Houston, Houston, Texas 77204
K. Matsuishi
Affiliation:
Department of Physics, Texas Center for Superconductivity, University of Houston, Houston, Texas 77204
X. Quan
Affiliation:
Department of Physics, Texas Center for Superconductivity, University of Houston, Houston, Texas 77204
Get access

Abstract

In this paper the mechanism of phase transition and structural relaxation are elucidated by means of model experiments in the differential scanning calorimeter. Materials for this study were varied in structure and oxygen content by the introduction of Ni for Cu, through co-precipitation of oxolate gels, calcination, and sintering in ambient atmosphere. Both relaxation and phase transition are revealed by scrutinizing the heating rate dependence of heat capacity, and they seem to occur contemporaneously. Two higher order transitions are observed and are characterized by activation energies of 186 kJ/mole and 550 kJ/mole at the low and high temperatures, respectively. Perhaps the first transition is of a displacive type and occurs in anticipation of a reconstructive structural change from a fourfold chain to a sixfold sheet-like configuration. It is delineated by a change in relaxation kinetics from a localized type to a cooperative type with activation energies of 36 and 10 kJ/mole, respectively. The cooperative relaxation occurs at higher temperatures and is kinetically continuous across the reconstructive transition region. The structure characteristic exponent has a value of 0.70 for both localized and cooperative relaxation and resembles the two-dimensional relaxation often observed in depolymerized glasses. With kinetic impediment the transition region seems to approach a lambda-like behavior. In the subtransitional region, impediments in relaxation are useful in delineating oxygen stoichiometric differences between samples. The above discussion is supported by the structural and chemical characteristics that were gathered by x-ray powder diffraction, Raman spectroscopy, scanning electron microscopy and microprobe, and low temperature resistance measurements on Y123 samples containing 5 and 10 at. % Ni, respectively.

Type
Articles
Copyright
Copyright © Materials Research Society 1991

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

1.Jorgensen, J. D., Beno, M. A., Hinks, D. G., Soderholm, L., Volin, K. J., Hitterman, R. L., Grace, J. D., and Schuller, Ivan K., Phys. Rev. 36, 36083616 (1987).CrossRefGoogle Scholar
2.Gallagher, P. K., O'Bryan, H. M., Sunshine, S. A., and Murphy, D. W., Mater. Res. Bull. XXII, 9951006 (1987).CrossRefGoogle Scholar
3.Deymier, P. A., Phys. Rev. B 38, 65966603 (1988).CrossRefGoogle Scholar
4.Ota, S. B. and Rao, T. V. C., Physica C 153–155, 257258 (1988).CrossRefGoogle Scholar
5.Jorgensen, J. D., Shaked, H., Hinks, D. G., Dabrowski, B., Veal, B. W., Paulikas, A. P., Nowicki, L. J., Crabtree, G. W., Kwok, W. K., and Nunez, L. H., Physica C 153155, 578–581 (1988).CrossRefGoogle Scholar
6.Nowick, A. S. and Berry, B. S., Anelastic Relaxation in Crystalline Solids (Academic Press, New York, 1972), pp. 156224.Google Scholar
7.Burns, R. G., Minerological Applications of Crystal Field Theory (Cambridge University Press, Cambridge, 1970), pp. 427.Google Scholar
8.Krishnamurthy, K. V. and Harris, G. M., Chem. Rev. 61, 213240 (1961).CrossRefGoogle Scholar
9.Cooper, S. L. and Klein, M. V., Comments Cond. Mat. Phys. 15, 99124 (1990).Google Scholar
10.Goldstein, J. I. and Yakowitz, H., Practical Scanning Electron Microscopy (Plenum Press, New York, 1977), pp. 327372.Google Scholar
11.Rao, C. N. R. and Rao, K. J., Phase Transitions in Solids (McGraw- Hill, New York, 1978), p. 231.Google Scholar
12.Parsonage, N. G. P. and Staveveley, L. A. K., Disorder in Crystals (Oxford University Press, London, 1978), p. 18.Google Scholar
13.Shewman, P. G., Diffusion in Solids (McGraw-Hill, New York, 1963), pp. 4085.Google Scholar
14.Stebbins, J. F., Carmichael, I. S. E., and Moret, L. K., Contrib. Mineral Petrol. 86, 131148 (1984).CrossRefGoogle Scholar
15.Tarascon, J. M., Barboux, P., Miceli, P. F., Greene, L. H., Hull, G. W., Eibschutz, M., and Sunshine, S. A., Phys. Rev. B 37, 7458 (1988).CrossRefGoogle Scholar
16.Maeno, Y., Tomita, T., Kyogoku, M., Awaji, S., Aoki, Y., Hoshino, K., Minami, A., and Fujita, T., Nature 328, 512 (1987).CrossRefGoogle Scholar
17.Kajitani, T., Kusaba, K., Kikuchi, M., Syono, Y., and Hirabayashi, M., Jpn. J. Appl. Phys. 27, p. L354 (1988).CrossRefGoogle Scholar
18.Bringley, J. E., Chen, T. M., Averill, B. A., Wong, K. M., and Poon, S. J., Phys. Rev. B 38, 2432 (1988).CrossRefGoogle Scholar
19.Kelley, K. K., U. S. Bureau of Mines Bull. 584, 1232 (1960).Google Scholar
20.Helgeson, C. J., Delany, J. M., Nesbitt, H. W., and Bird, D. K., Am. J. Sci. 278-A, 229 (1978).Google Scholar
21.Prigogine, I., Defay, R., and Everett, D. H., Chemical Thermodynamics (Longmans, London, 1965), pp. 291310.Google Scholar
22.Moynihan, C. T., Macedo, P. B., Montrose, C. J., Gupta, P. K., DeBolt, M. A., Dill, J. F., Dom, B. E., Drake, P. W., Easteal, A. J., Elterman, P. B., Moeller, R. P., Sasabe, H., and Wilder, J. A., Anals New York Acad. Sci. 279, 1535 (1976).CrossRefGoogle Scholar
23.Brawer, S., Relaxation in Viscous Liquids and Glasses (The Am. Ceram. Soc, Westerville, OH, 1985), pp. 3761.Google Scholar
24.Matusita, K. and Sakka, S., Phys. Chem. Glasses 20, 8184 (1979)Google Scholar