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Ellipsometric study of yba2cu3o(7-x) laser ablated and co-evaporated films
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Vitta, S. Sieg, R. E. Stan, M. A. Warner, J. D. Alterovitz, S. A. |
| Copyright Year | 1990 |
| Description | High temperature superconducting films of YBa2Cu3O(7-x) (YBCO were grown on SrTiO3, LaA1O3, and YSZ substrates using two techniques: excimer laser ablation with in situ annealing and co-evaporation of Y, Cu, and BaF2 with ex-situ annealing. Film thicknesses were typically 5000 A, with predominant c-axis alignment perpendicular to the substrate. Critical temperatures up to Tc(R=O)=90 K were achieved by both techniques. Ellipsometric measurements were taken in the range 1.6 to 4.3 eV using a variable angle spectroscopic ellipsometer. The complex dielectric function of the laser ablated films was reproducible from run to run, and was found to be within 10 percent of that previously reported for (001) oriented single crystals. A dielectric overlayer was observed in these films, with an index of refraction of approximately 1.55 and nearly zero absorption. For the laser ablated films the optical properties were essentially independent of substrate material. The magnitude of the dielectric function obtained for the co-evaported films was much lower than the value reported for single crystals, and was sample dependent. |
| File Size | 401443 |
| Page Count | 10 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19900017366 |
| Archival Resource Key | ark:/13960/t3gx96v9q |
| Language | English |
| Publisher Date | 1990-01-01 |
| Access Restriction | Open |
| Subject Keyword | Solid-state Physics Spectroscopy Annealing Dielectric Properties Refractivity Evaporation Ytterbium Compounds Dielectrics High Temperature Film Thickness Ablation Substrates Single Crystals Alignment Superconducting Films Optical Properties Barium Oxides Excimer Lasers Critical Temperature Ellipsometers Copper Oxides Laser Applications Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
