Growth of Bi2Sr2Cu1Ox films by laser ablation

The formation and the properties of thin BiSrCuO films grown on MgO single crystal substrates by the pulsed laser ablation of a Bi2Sr2Cu1O6 target hav e been studied. The precise influence of the oxygen pressure and substrate temperature on the atomic composition, nature and structure of the grown ph ases, crystalline quality and superconductivity of the films has been analy zed. In the 600-750 degrees C temperature range and 0.05-0.5 mbar oxygen pr essure range, highly textured films of the 2201 phase (Bi2Sr2Cu1O6 phase) w ere formed despite large composition deviations (Bi enrichment and Sr deple tion) with respect to the ideal composition. A high crystalline quality was evidenced for films grown at low and intermediate pressure and high temper ature. chi(min) values in the films deduced from channeling experiments wer e similar to the case of single crystal material. Despite this high crystal line quality, incomplete or very low T-c superconducting transitions were o bserved in the resistivity measurements. (C) 1999 Published by Elsevier Sci ence B.V. All rights reserved.