X-ray photoelectron spectroscopy of uv laser irradiated sapphire and alumina

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Journal of Materials Research; (United States)

DOI:https://doi.org/10.1557/JMR.1994.2251· OSTI ID:7039653

Pedraza, A J; Park, J W ^[1]; Meyer, III, H M ^[2]; Braski, D N ^[3]

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1. Department of Materials Science and Engineering, The University of Tennessee, Knoxville, Tennessee 37996-2200 (United States)
2. Martin Marietta Energy Systems, P. O. Box 2009, Oak Ridge, Tennessee 37831 (United States)
3. Oak Ridge National Laboratory, P. O. Box 2008, Oak Ridge, Tennessee 37831-6056 (United States)

X-ray photoelectron spectroscopy (XPS) was performed on as-received, annealed, and laser-irradiated sapphire and alumina in order to study effects of different treatments on surface chemistry and properties. Laser irradiations at 308 nm were performed in air and in a reducing atmosphere (Ar-4% hydrogen). Atomic percentages of carbon, aluminum, and oxygen were measured in all specimens;particular attention was paid to percentages of oxygen in the oxide and hydroxyl state. XPS analyses clearly established that a very thin film of metallic aluminum is formed on the surface of both alumina and sapphire substrates when irradiated under a reducing atmosphere. However the film is discontinuous because it is electrically insulating. Substrates irradiated in air have metallic aluminum only for fluences below 0.4 J/cm[sup 2]. The valence band photoemission spectra of as-received, annealed, and laser-irradiated specimens were measured. In irradiated specimens, the width of the valence band spectra was found to decrease by [similar to]10%. One possible cause of this decrease is the generation of point defects during laser irradiation. Electroless copper deposition occurs on sapphire and alumina substrates if their surface has been activated by laser irradiation. The time required for copper deposition was monitored by measuring the electrical resistivity in the irradiated area while the substrates were immersed in an electroless bath. The kinetics of deposition on laser-activated substrates and the XPS results show that the presence of metallic aluminum accelerates the deposition process. However, the presence of aluminum is not the sole reason for laser activation in alumina. Very strong metal-ceramic bonding is produced after thermal annealing of samples having preirradiated substrates. This result is explained in terms of the excess oxygen that is present at the ceramic surface after irradiation.

• OSTI ID: 7039653
• Journal Information: Journal of Materials Research; (United States), Journal Name: Journal of Materials Research; (United States) Vol. 9:9; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360206* -- Ceramics
Cermets
& Refractories-- Radiation Effects
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BONDING
CARBON
CHALCOGENIDES
COPPER
CORUNDUM
DEPOSITION
ELECTROMAGNETIC RADIATION
ELECTRON SPECTROSCOPY
ELEMENTS
FABRICATION
FILMS
IONIZING RADIATIONS
JOINING
LASER RADIATION
METALS
MINERALS
NONMETALS
OXIDE MINERALS
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHOTOELECTRON SPECTROSCOPY
PHYSICAL RADIATION EFFECTS
RADIATION EFFECTS
RADIATIONS
SAPPHIRE
SPECTROSCOPY
THIN FILMS
TRANSITION ELEMENTS
ULTRAVIOLET RADIATION
X RADIATION