IN-SITU HETEROEPITAXIAL GROWTH OF CEO2 YBA2CU3O7 FILMS ON SAPPHIRE BYINJECTION CVD/

A new principle for stable generation of precursors from volatile vapo urs in a CVD reactor was developed for in-situ deposition of bilayers CeO2/YBa2Cu3O7 on sapphire (<1(1)over bar 02>) substrates. This princi ple is based on computer controlled injection of precise microdoses of liquid precursors or solutions of solid precursors in an organic solv ent in an evaporator of CVD reactor, ''flash evaporation'' and rapid v apour transport to the deposition zone. Application of several injecti ons sources permits in-situ deposition of multilayered oxide structure s, Heteroepitaxially grown CeO2 (approximate to 0.2 mu m)/YBa2Cu3O7 (0 .5-1 mu m)/Al2O3 structures exhibited a sharp superconducting transiti on at about 90 K (Delta T = 0.6-1 K) and had a critical current densit y of about 10(5) A/cm(2).