YBa2Cu3O7−δ-thin films on sapphire with buffer layers of CeO2

✍ Scribed by M. Maul; B. Schulte; P. Häussler; H. Adrian

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 166 KB
• Volume: 194-196
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(94)91642-x

✦ Synopsis

Epitaxial CeO2 buffer layers and YBa2Cu307_~ thin films have been grown in situ on (1].02) sapphire by electron beam evaporation. Buffer layers of only 20 nm thickness inhibit interdiffusion between YBa2 Cu3 O7-6 and A12 03 as determined by depth profiling using x-ray photoelectron spectroscopy. The layers show smooth surfaces and narrow interfaces. High lattice perfection of the CeO2 layer has been shown by x-ray diffraction. The first time Laue oscillations up to ninth order have been observed in thin CeO2 buffer layers. YBa2Cu307_o films grown on these buffer layers reveal Tc--88=t=0.5 K, p(300 K)----380 ~tflcm, and jc (77 K, 0 T)---1.3 x 106 A/cm 2 .