skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Physics and diagnostics of laser ablation plume propagation for high-{Tc} superconductor film growth

Abstract

The formation, composition and propagatin of laser-produced plasmas used for pulsed laser deposition (PLD) of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x} have been studied under film growth conditions. Four complementary spatially- and temporally-resolved in situ diagnostic techniques are applied to characterize the expansion of the laser plume into both vacuum and ambient gases: optical emission and absorption spectroscopy, fast ion probe measurements, and fast photography with a gated, image-intensified CCD array (ICCD) camera system. Transient optical absorption spectroscopy reveals large densities of ground state atoms, ions, and molecules in the plume as well as a slower component to the plume transport than is indicated by the plasma fluorescence and ion current. Ablation into background gases results in scattering attenuation of the laser plume. The exponential attenuation of the positive ion flux transmitted through 50--300 m Torr background oxygen is measured and used to define an overall ion-oxygen reaction cross section of {sigma}{sub {eta}-O{sub 2}} = 2.3 {times} 10{sup {minus}16} cm{sup 2} under the described film growth conditions. The slowing of the laser plasma and formation of shock structures due to collisions with the ambient gas are described using ion probe measurements and ICCD photographic comparisons of expansion into vacuum and backgroundmore » oxygen. At the pressures used for PLD, distance-time (R-t) plots derived from the photographs and ion probe waveforms indicate that the higher pressure plume initially expands through the ambient gas in accordance with a drag model experiencing little slowing until a visible shock structure forms. Following a transition period, in which the plume appears to have two components, a single component shock structure propagates in better agreement with a shock, or blast wave model.« less

Authors:
Publication Date:
Research Org.:
Oak Ridge National Lab., TN (United States)
Sponsoring Org.:
USDOE, Washington, DC (United States)
OSTI Identifier:
10134576
Report Number(s):
CONF-920439-3
ON: DE92009386
DOE Contract Number:  
AC05-84OR21400
Resource Type:
Conference
Resource Relation:
Conference: 19. international conference on metallurgical coatings and thin films (ICMCTF),San Diego, CA (United States),6-10 Apr 1992; Other Information: PBD: Mar 1992
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 70 PLASMA PHYSICS AND FUSION TECHNOLOGY; YTTRIUM OXIDES; LASER-PRODUCED PLASMA; BARIUM OXIDES; COPPER OXIDES; HIGH-TC SUPERCONDUCTORS; EMISSION SPECTROSCOPY; ABSORPTION SPECTROSCOPY; PLUMES; ION PROBES; ULTRAHIGH-SPEED PHOTOGRAPHY; ABLATION; SUPERCONDUCTING FILMS; 360201; 665300; 700320; PREPARATION AND FABRICATION; INTERACTIONS BETWEEN BEAMS AND CONDENSED MATTER; PLASMA DIAGNOSTIC TECHNIQUES AND INSTRUMENTATION

Citation Formats

Geohegan, D B. Physics and diagnostics of laser ablation plume propagation for high-{Tc} superconductor film growth. United States: N. p., 1992. Web.
Geohegan, D B. Physics and diagnostics of laser ablation plume propagation for high-{Tc} superconductor film growth. United States.
Geohegan, D B. Sun . "Physics and diagnostics of laser ablation plume propagation for high-{Tc} superconductor film growth". United States.
@article{osti_10134576,
title = {Physics and diagnostics of laser ablation plume propagation for high-{Tc} superconductor film growth},
author = {Geohegan, D B},
abstractNote = {The formation, composition and propagatin of laser-produced plasmas used for pulsed laser deposition (PLD) of Y{sub 1}Ba{sub 2}Cu{sub 3}O{sub 7-x} have been studied under film growth conditions. Four complementary spatially- and temporally-resolved in situ diagnostic techniques are applied to characterize the expansion of the laser plume into both vacuum and ambient gases: optical emission and absorption spectroscopy, fast ion probe measurements, and fast photography with a gated, image-intensified CCD array (ICCD) camera system. Transient optical absorption spectroscopy reveals large densities of ground state atoms, ions, and molecules in the plume as well as a slower component to the plume transport than is indicated by the plasma fluorescence and ion current. Ablation into background gases results in scattering attenuation of the laser plume. The exponential attenuation of the positive ion flux transmitted through 50--300 m Torr background oxygen is measured and used to define an overall ion-oxygen reaction cross section of {sigma}{sub {eta}-O{sub 2}} = 2.3 {times} 10{sup {minus}16} cm{sup 2} under the described film growth conditions. The slowing of the laser plasma and formation of shock structures due to collisions with the ambient gas are described using ion probe measurements and ICCD photographic comparisons of expansion into vacuum and background oxygen. At the pressures used for PLD, distance-time (R-t) plots derived from the photographs and ion probe waveforms indicate that the higher pressure plume initially expands through the ambient gas in accordance with a drag model experiencing little slowing until a visible shock structure forms. Following a transition period, in which the plume appears to have two components, a single component shock structure propagates in better agreement with a shock, or blast wave model.},
doi = {},
url = {https://www.osti.gov/biblio/10134576}, journal = {},
number = ,
volume = ,
place = {United States},
year = {1992},
month = {3}
}

Conference:
Other availability
Please see Document Availability for additional information on obtaining the full-text document. Library patrons may search WorldCat to identify libraries that hold this conference proceeding.

Save / Share: