TY - JOUR
T1 - Thin film materials exposure to low earth orbit aboard space shuttle
AU - Synowicki, R. A.
AU - Hale, Jeffrey S.
AU - Spady, Blaine
AU - Reiser, Mike
AU - Nafis, S.
AU - Woollam, John A.
N1 - Funding Information:
The authors extend thanks to NASA Lewis Research Center for funding this work under Grant NAG-3-95. The Nebraska Space Grant Consortium also contributed funding for student support on this project. The article reflects the work of many individuals who gave their time and resources to make this project complete. The authors would like to thank Rod Dillon and Hsuing Chen of the University of Nebraska-Lincoln Center for Microelectronic and Optical Materials Research (UNL CMOMR) for preparation and characterization of the polycrystalline diamond films studied in this work. Thanks to Ned lanno of the UNL CMOMR for use of his diamondlike carbon deposition equipment, and to Carlos R. Morrison and Sam Alterovitz of NASA-Lewis for contributing diamondlike carbon films. Jim T. Visentine at Johnson Space Center was kind enough to allow reproduction of his predicted orbital fluences.
PY - 1995
Y1 - 1995
N2 - To study the effects of Atomic Oxygen on various thin film materials, fourteen thin film samples were exposed to the corrosive environment of low Earth orbit. Total exposure was 42 hours, resulting in a nominal atomic oxygen fluence of 2.2 x 1020 atoms/cm2. The films included aluminum, diamondlike carbon, diamond, and multilayer stacks. Included are experimental details of sample preparation, exposure, and post-flight results. Pre-flight characterization techniques included Variable Angle Spectroscopic Ellipsometry, optical reflectance and transmittance, Atomic Force Microscopy, and Raman scattering. Post-flight analysis repeated pre-flight characterization. Aluminum films resisted degradation. Surface contaminants were identified using Auger Electron Spectroscopy. Contaminants were Si02, fluorine, and sulfur which most likely result from degradation of cargo bay lining, waste water dumps, and outgassing. Diamondlike carbon films were completely etched away during exposure. Polycrystalline diamond films were extremely resistant to atomic oxygen degradation, showing no post-flight structural, compositional, or mass changes. Aluminum films 23.5 nm thick simultaneously protect silver reflecting layers from oxidation and increase the ultraviolet reflectance of the stack. Decreasing the aluminum thickness to 7.5 nm resulted in complete oxidation during exposure and failure as a protective coating.
AB - To study the effects of Atomic Oxygen on various thin film materials, fourteen thin film samples were exposed to the corrosive environment of low Earth orbit. Total exposure was 42 hours, resulting in a nominal atomic oxygen fluence of 2.2 x 1020 atoms/cm2. The films included aluminum, diamondlike carbon, diamond, and multilayer stacks. Included are experimental details of sample preparation, exposure, and post-flight results. Pre-flight characterization techniques included Variable Angle Spectroscopic Ellipsometry, optical reflectance and transmittance, Atomic Force Microscopy, and Raman scattering. Post-flight analysis repeated pre-flight characterization. Aluminum films resisted degradation. Surface contaminants were identified using Auger Electron Spectroscopy. Contaminants were Si02, fluorine, and sulfur which most likely result from degradation of cargo bay lining, waste water dumps, and outgassing. Diamondlike carbon films were completely etched away during exposure. Polycrystalline diamond films were extremely resistant to atomic oxygen degradation, showing no post-flight structural, compositional, or mass changes. Aluminum films 23.5 nm thick simultaneously protect silver reflecting layers from oxidation and increase the ultraviolet reflectance of the stack. Decreasing the aluminum thickness to 7.5 nm resulted in complete oxidation during exposure and failure as a protective coating.
UR - http://www.scopus.com/inward/record.url?scp=0029184958&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029184958&partnerID=8YFLogxK
U2 - 10.2514/3.26580
DO - 10.2514/3.26580
M3 - Article
AN - SCOPUS:0029184958
SN - 0022-4650
VL - 32
SP - 97
EP - 102
JO - Journal of Spacecraft and Rockets
JF - Journal of Spacecraft and Rockets
IS - 1
ER -