Microstructural study of yttria stabilized zirconia buffered sapphire for YBa2Cu3O7−δ thin films
1996; American Institute of Physics; Volume: 79; Issue: 2 Linguagem: Inglês
10.1063/1.360876
ISSN1520-8850
AutoresM. S. Ramachandra Rao, C. P. D’Souza, P. R. Apte, R. Pinto, L. C. Gupta, Sudha Srinivas, Anil K. Bhatnagar,
Tópico(s)Physics of Superconductivity and Magnetism
ResumoYttria stabilized zirconia (YSZ) buffer layers were grown by rf-magnetron sputtering on the r (11̄02) plane of sapphire for YBa2Cu3O7−δ (YBCO) thin film deposition. Microstructural changes of YSZ buffer layers grown using different sputtering conditions (5, 10, and 20 mTorr; Ar/O2 gas mix ratio of 9:1 and 1:1) were monitored by atomic force microscopy (AFM). Films grown using a lower oxygen partial pressure (5 mTorr) and a higher Ar/O2 ratio (9:1) showed smooth surface morphology and the average surface roughness increased with an increase in oxygen partial pressure. YBCO films in situ grown by pulsed laser deposition on sapphire with a YSZ buffer layer deposited using optimized sputtering parameters (5 mTorr gas pressure, 9:1 Ar/O2 ratio) yielded the highest critical density, Jc≊4.5×106 A cm−2 at 77 K. An excellent correlation between microstructure and Jc has been found and AFM has proved to be important for the study of the microstructure of films.
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