SINGLE CRYSTAL GROWTH OF Sr₂RuO₄ BY LASER-HEATED PEDESTAL GROWTH (LHPG). Y. P. Mascarenhas, D. Reyes Ardila, M. R. B. Andreeta, S. L. Cuffini, A. C. Hernandes, J. P. Andreeta, Instituto de Fisica de São Carlos, Universidade de São Paulo, C. P. 369, 13560-970, Sao Carlos, SP, Brazil

Sr₂RuO₄ was reported in 1994 (1) as the first non-cuprate layered perovskite that is superconducting near 1K. Although its Tc is so low, this layered oxide compound is the first directly relevant superconductor, without copper, for comparison with the high-Tc cuprates. Besides, this results demonstrated that the presence of copper is not a prerequisite for the existence of superconductivity in layered perovskite compounds. Up to now, the method used in the preparation of single crystal was floating zone melting (2). We report, for the first time to our knowledge, the growth of Sr₂RuO₄ single crystal fibers by Laser-Heated Pedestal Growth (LHPG) technique. The fibers obtained were up to 20mm in length with 0.8-1.0 mm in diameter. They were easily cleaved, yielding plate-like crystal with (001) surface. Sr₂RuO₄ compound has K₂NiO₄ structure with space group I4/mmm and lattice parameters a = 3.861 (1) A and c=12.701(3)A, which are in good agreement with the previous reports (3). The single crystal fibers were characterized by SEM, EPMA and X-ray diffraction using Laue method and single crystal difractometer (CAD-4 Enraf-Nonius).

(1) Y. Maeno, H. Hashimoto, K. Yoshida, S. Nishizaki, T. Fujita, J. G. Bednorz and F. Lichtenberg, Nature Vol. 372, p. 532 Dec. (1994).

(2) F. Lichtenberg, A. Catana, J. Mannhart and D. G. Schlom, Appl. Phys. Lett. 60, 1138-1140 (1992).

(3) L. Walz, F. Lichtenberg, Acta. Cryst. C49, 1268-1270 (1993).

Acknowledgement: FAPESP, CAPES, CNPq, FINEP.