GROWTH OF [YBA2CU3O7-DELTA]M [PRBA2CU3-XGAXO7-DELTA]N SUPERLATTICES BY PULSED-LASER DEPOSITION/

PrBa2Cu3-xGaxO7-delta thin films up to x=0.2 and YBa2Cu3O7-delta/PrBa2 Cu2.8Ga0.2O7-delta superlattices have been grown by pulsed laser depos ition (PLD) on {100} SrTiO3 substrate. The resitance of PrBa2Cu2.8Ga0. 2O7-delta is 500 times higher at 77 K than the one of unsubstituted Pr Ba2Cu3O7-delta. At a growth temperature of 785-degrees-C, the multilay ers have c-axis normal to the substrate surface and satellite peaks ha ve been observed up to i = +/- 3 on X-ray diffraction spectra. At a lo wer growth temperature the structure becomes oriented with a-axis norm al to the growth interface. Secondary-ion mass spectrometry reveals no interdiffusion between Y and Pr and no diffusion of Ga into the YBa2C u3O7-delta layer. The 15% RBS minimum yield reoorded for the superlatt ice indicates highly oriented growth. T(c) is around 10 K lower than t he one of the equivalent decoupled multilayers grown from unsubstitute d PrBa2Cu3O7-delta.