Physica C 162-164 (1989) 115-116 North-Holland ZERO RESISTIVITY AT 81K IN BSCCO FILMS GROWN FROM LIQUID KCI SOLUTIONS G. BALESTRINO 1 1 3 2 2 2 , R. DI LEO , M. MARINELLI , E. MILANI , A. PAOLETTI , P. PAROLI 1Dipartimento di Fisica dell'Universit~ di Salerno, Salerno, Italy 2 Dipartimento di Ingegneria Meccanica, II Universit~ di Roma, 1-00173 Roma, Italy 3 Istituto I.E.S.S. del C.N.R., Via Cineto Romano 42, 1-00156 Roma, Italy Textured films of "BSCCO 2212" , with zero resistivity at 81 K, have been grown from KCI liquid solutions, onto (lll)-oriented substrates of Gadolinium Gallium Garnet. This technique is particularly promising to grow large epitaxial films of both the "2212" and the "2223" phases of BSCCO. I. INTRODUCTION Since the discovery of the new class of high temperature superconductors much effort has been devoted to the realization of thin films suitable for the realization of solid state devices, like SQUID's and particle detectors, operating at liquid nitrogen temperatures. Epitaxial and textured films of high temperature superconductors have been obtained by various techniques ( namely evaporation, sputtering, and laser ablation) on various substrates (A1203, MgO, SrTiO 3 ). Recently we have reported on the growth from liquid phase of films of Bi Sr CaCu 0 ("BSCCO") on a 2 2 2 8+x gadolinium gallium garnet substrate (GGG) with zero resistance at 50 K I. Here we report a more extensive investigation on this growth technique and show that BSCCO films with zero resistance at 81K can be obtained. 2. EXPERIMENTAL Recently very thin single crystals of the BSCCO phase (having thicknesses about few microns) were grown from flux using a saturated 0921-4534 / 89/$03.50 © Elsevier Science Publishers B.V. (North-Holland) solution of the constituent oxides of BSCCO in molten KCI 2. The choise of KCl as a solvent was suggested by its solubility in water. Such feature makes easy to separate BSCCO single crystals from the solidified melt without using a mechanical and often destructive technique. Our growth technique is very similar to that widely used for the growth of garnet films from PbO-B203 fluxes 3. The typical procedure is described below. The Bi oxide, the Cu oxide, the Sr and the Ca carbonates (all at least 99.5% pure) were weighed in the atom ratios Bi:Sr:Ca:Cu=2:2:l:2, mixed in an agathe mortar 3 placed in a i00 em crucible and then annealed few hours at 850 °C. The partially reacted powders were then quenched to room temperature and the KCI" was added on the top of the prereacted powders. The molar ratio between the solvent and the solute was about 50. The crucible was then placed in a vertical tubolar furnace. For the given value of the ratio solvent to solute the solution is saturated by 2 the BSCCO constituent oxides which largely remain at the bottom of the crucible. To