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Thermal characterization of GdSr2RuCu2Oy-based mixtures in the GdSr2RuO6–CuO pseudobinary system

Published online by Cambridge University Press:  31 January 2011

Marcello Gombos ,
Regina Ciancio ,
Sandro Pace  and
Antonio Vecchione
Marcello Gombos*
Affiliation:
Laboratorio Regionale SuperMat CNR-INFM, and Università degli Studi di Salerno, Dipartimento di Fisica “E.R. Caianiello,” Via Salvador Allende, I-84081 Baronissi (Salerno), Italia
Regina Ciancio
Affiliation:
Laboratorio Regionale SuperMat CNR-INFM, and Università degli Studi di Salerno, Dipartimento di Fisica “E.R. Caianiello,” Via Salvador Allende, I-84081 Baronissi (Salerno), Italia
Sandro Pace
Affiliation:
Laboratorio Regionale SuperMat CNR-INFM, and Università degli Studi di Salerno, Dipartimento di Fisica “E.R. Caianiello,” Via Salvador Allende, I-84081 Baronissi (Salerno), Italia
Antonio Vecchione
Affiliation:
Laboratorio Regionale SuperMat CNR-INFM, and Università degli Studi di Salerno, Dipartimento di Fisica “E.R. Caianiello,” Via Salvador Allende, I-84081 Baronissi (Salerno), Italia
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Fundamental to investigating the coexistence of superconductivity and magnetic ordering in GdSr2RuCu2Oy(Gd1212) is the fabrication of macroscopic crystallographically oriented samples. To achieve this, we need to identify the conditions in which Gd1212 incongruent melting reaction, producing solid GdSr2RuO6(Gd1210) in Cu-rich liquid, dominates over decomposition due to RuO2sublimation. Only in these conditions is it possible, indeed, to grow oriented samples by any melting and resolidifying technique. Moreover, the optimal mixture of Gd1212 and its melting products has to be identified to perform melt-textured or flux-flow growth. By means of thermogravimetric and differential thermal analysis (TG–DTA) we analyzed, up to 1200 °C in air, several mixtures of Gd1212 with Gd1210 or CuO, performing a scan of the entire CuO–Gd1212–Gd1210 coexistence line of the Gd–Sr–Ru–Cu–O phase diagram. Gd1212 melting temperatures have shown a certain dependence on composition, decreasing about 30 °C for high Gd1210 content samples and about 20 °C for high CuO content samples with respect to pure Gd1212. A huge undercooling was observed for resolidification processes that were revealed to start at temperatures around 990 °C. Measurements proved that in this range of temperatures in air, no mass is lost at the end of each melting process, so that they are not affected by RuO2sublimation. A strong dependence on the atmosphere has also been observed for pure Gd1212, melting temperature decreasing by more than 80 °C from 100% O2atmosphere to He atmosphere (less than 10−2% O2). Measurements revealed that high O2partial pressures favor RuO2sublimation, whereas low oxygen atmospheres prevent resolidification.

Keywords

Differential thermal analysis (DTA)RuSuperconducting
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 6 , June 2007 , pp. 1579 - 1584
Copyright
Copyright © Materials Research Society2007

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References

REFERENCES

1Ruthenate and rutheno-cuprate materials: Theory and experiments, in LNP Series, 603 (25–27 Oct, 2001, Vietri sul Mare, Italy), (Springer Verlag, Berlin, 2002)Google Scholar
2Bernhard, C., Tallon, J.L., Niedermeier, Ch., Blasius, Th., Golnik, A., Brücher, E., Kremer, R.K., Noakes, D.R., Stronach, C.E.Ansaldo, E.J.: Coexistence of ferromagnetism and superconductivity in the hybrid ruthenate-cuprate compound RuSr2GdCu2O8studied by muon spin rotation and dc magnetization. Phys. Rev. B 59, 14099 1999CrossRefGoogle Scholar
3Tallon, J., Bernhard, C., Bowden, M., Gilberd, P., Stoto, T.Pringle, D.: Coexisting ferromagnetism and superconductivity in hybrid rutheno-cuprate superconductors. IEEE Trans. Appl. Supercon. 9, 1696 1999CrossRefGoogle Scholar
4McLaughlin, A.C.Attfield, J.P.: Tuning of the ferromagnetic and superconducting transitions by tin-doping in RuSr2GdCu2O8. Phys. Rev. B 60, 14605 1999CrossRefGoogle Scholar
5Lynn, J.W., Keimer, B., Ulrich, C., Bernard, C.Tallon, J.L.: Antiferromagnetic ordering of Ru and Gd in superconducting RuSr2GdCu2O8. Phys. Rev. B 61, R14964 2000CrossRefGoogle Scholar
6Nakamura, K.Freeman, A.J.: Canted ferromagnetism in RuSr2GdCu2O8. Phys. Rev. B 66, 140405 2002CrossRefGoogle Scholar
7Vecchione, A., Zola, D., Carapella, G., Gombos, M., Pace, S., Costabile, G.Noce, C.: Low frequency transport measurements in GdSr2RuCu2O8. Eur. Phys. J. B 31, 151 2003CrossRefGoogle Scholar
8Attanasio, C., Salvato, M., Ciancio, R., Gombos, M., Pace, S., Uthayakumar, S.Vecchione, A.: Pinning energy and irreversibility line in superconducting GdSr2RuCu2Ox. Physica C 411, 126 2004CrossRefGoogle Scholar
9Bauernfeind, L., Widder, W.Braun, H.F.: Superconductors consisting of CuO2and RuO2layers. J. Low Temp. Phys. 105, 1605 1996CrossRefGoogle Scholar
10Matveev, A.T., Sader, E., Duppel, V., Kulakov, A., Maljuk, A., Lin, C.T.Habermeier, H.U.: Decomposition of RuSr2GdCu2O8phase under high-temperature treatment. Physica C 403, 231 2004CrossRefGoogle Scholar
11Gombos, M., Vecchione, A., Ciancio, R., Sisti, D., Uthayakumar, S.Pace, S.: Melt-textured GdSr2RuCu2Oxsamples: Preliminary results. Physica C 408–410, 189 2004CrossRefGoogle Scholar
12Ciancio, R., Gombos, M., Vecchione, A., Fittipaldi, R.Pace, S.: Morphological and structural study on GdSr2RuCu2O8melt-textured samples. IEEE Trans. Appl. Supercon. 15, 3149 2005CrossRefGoogle Scholar
13Gombos, M., Ciancio, R., Vecchione, A.Pace, S.: (in press)Google Scholar
14Tedesco, C., Pastore, H.O., Frache, A., Gombos, M., Immirzi, A., Vecchione, A.Marchese, L.: A comparison of the processes involved in the direct synthesis of GdSr2RuCu2Ox and NdSr2RuCu2Oyperovskites. Physica C 408–410, 193 2004CrossRefGoogle Scholar
15Mele, P.: personal communicationGoogle Scholar
16Gombos, M., Gomis, V., Vecchione, A., Ciancio, R., Fittipaldi, R., Carrillo, A.E., Pace, S.Obradors, X.: Mechanical fragility and tri dimensional crack structure in NdBaCuO top seeded and multi-seeded melt-textured samples. IEEE Trans. Appl. Supercon. 15, 3137 2005CrossRefGoogle Scholar
17Matveev, A.T., Kulakov, A., Maljuk, A., Lin, C.T.Habermeier, H.U.: Phase stability limit of RuSr2GdCu2O8at various partial oxygen pressures. Physica C 400, 53 2003CrossRefGoogle Scholar