DEPOSITION OF HIGH-QUALITY YBA2CU3O7-X FILMS ON ULTRATHIN (12 MU-M THICK) SAPPHIRE SUBSTRATES FOR INFRARED DETECTOR APPLICATIONS

High quality epitaxial YBa2Cu3O7-x (YBCO) thin films have been deposit ed on 12 mu m thick (1 (1) over bar 02) oriented sapphire substrates u sing a CeO2 buffer layer. Both layers were deposited by pulsed laser d eposition (PLD) using a blackbody-type heater, The YBCO films showed s uperconductive transition temperatures of 88-89.5 K and transition wid ths less than or equal to 0.5 K. Structural evaluation of the films in dicate that the YBCO films are c-axis oriented, with the YBCO (005) pe ak showing a rocking angle full width half-maximum (FWHM) of about 0.7 degrees. The phi-scans of the (103) YBCO peak indicate a high degree of in-plane epitaxy with no signs of high angle grain boundaries, The high quality of these films combined with the low heat capacity of the substrates, make these structures ideal for infrared detector applica tions. (C) 1995 American Institute of Physics.