Hostname: page-component-848d4c4894-nmvwc Total loading time: 0 Render date: 2024-06-18T09:12:28.777Z Has data issue: false hasContentIssue false

Characterization of Ground State Neutral and Ion Transport During Laser Ablation of 1:2:3 Superconductors by Transient Optical Absorption Spectroscopy

Published online by Cambridge University Press:  28 February 2011

David B. Geohegan
Affiliation:
Solid State Division, Oak Ridge National Laboratory, Oak Ridge TN 37831‐6056.
Douglas N. Mashburn
Affiliation:
Solid State Division, Oak Ridge National Laboratory, Oak Ridge TN 37831‐6056.
Get access

Abstract

Optical absorption in the plume produced by excimer laser ablation of Y1Ba2Cu3O7‐x under film growth conditions has been observed for the first time and used to characterize the transport of ground state Y, Ba, and Cu neutrals as well as Y+ and Ba+ ions. Spatially and temporally resolved absorption measurements (0.6 mm, 20 ns resolution) indicate significant ground state number densities at times following the laser pulse that are up to an order of magnitude longer than the duration of fluorescence from excited states. Time‐of‐flight absorbance profiles result in velocity distributions that are broadened significantly toward lower velocities and reveal a low velocity component (<10 5 cm s_1) to the ablation process which is not observed using emission spectroscopy. Electric ion probe measurements of the time dependence of Y+ ions confirm the existence of the new, slow velocity component. Electron densities >1016 cm‐3 in the white plasma close to the pellet have been estimated using spectrally broadened emission lines. The effects of oxygen ambient pressures and the detection of YO, BaO, and CuO also are reported. This technique is applicable as an situ monitor of the kinetic energy of ablated species during low temperature deposition of epitaxial 1:2:3 superconducting thin films.

Type
Research Article
Copyright
Copyright © Materials Research Society 1990

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Zheng, J. P., Huang, Z. Q., Shaw, D. T., and Kwok, H. S., Appl. Phys. Lett. 54, 280 (1989).Google Scholar
2 Zheng, J. P., Ying, Q. Y., Witanachchi, S., Huang, Z. Q., Shaw, D. T., and Kwok, H. S., Appl. Phys. Lett. 54, 954 (1989).Google Scholar
3 Geohegan, D. B. and Mashburn, D. N., Appl. Phys. Lett, (in press, Dec. 1989) and references cited therein. Ibid, in Proceedings of the Third Annual Conference on Superconductivity and Applications, Plenum Press, (1989, in press).Google Scholar
4 Principles of Laser Plasmas, edited by George Bekefi, John Wiley and Sons, (1976).Google Scholar
5 Hughes, T. P., Plasmas and Laser Light, John Wiley and Sons, New York, (1975).Google Scholar
6 Walkup, R. E., Jasinski, J. M., and Dreyfus, R. W., Appl. Phys. Lett. 48, 1690(1986).Google Scholar
7 Venkatesan, T. et.al., Appl. Phys. Lett. 53, 1431 (1988).Google Scholar