Cluster formation in laser-induced ablation and evaporation of solids observed by laser ionization time-of-flight mass spectrometry and scanning tunneling microscopy

Conference · Mon Jan 01 04:00:00 EST 1990

OSTI ID:6993622

Tench, R J; Balooch, M; Bernardez, L; Allen, M J; Siekhaus, W J ^[1]; Olander, D R; Wang, W ^[2]

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1. Lawrence Livermore National Lab., CA (USA)
2. Lawrence Berkeley Lab., CA (USA)

Laser ionization time-of-flight mass analysis (LIMA) used pulses (5ns) of a frequency-quadrupled Nd-YAG laser (266 nm) focused onto spots of 4--100 {mu}m diameter to ablate material, and a reflectron time of flight tube to mass-analyze the plume. The observed mass spectra for Si, Pt, SiC, and UO{sub 2} varied in the distribution of ablation products among atoms, molecules and clusters, depending on laser power density and target material. Cleaved surfaces of highly oriented pyrolytic graphite (HOPG) positioned at room temperature either 10 cm away from materials ablated at 10{sup {minus}5} Torr by 1--3 excimer laser (308 nm) pulses of 20 ns duration or 1 m away from materials vaporized at 10{sup {minus}8} Torr by 10 Nd-Glass laser pulses of 1 ms duration were analyzed by Scanning Tunneling Microscopy (STM) in air with {angstrom} resolution. Clusters up to 30 {angstrom} in diameter were observed. 8 refs., 4 figs.

• Research Organization: Lawrence Livermore National Lab., CA (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-7405-ENG-48; AC03-76SF00098
• OSTI ID: 6993622
• Report Number(s): UCRL-JC-103629; CONF-900466--31; ON: DE90010876
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201 -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
656002* -- Condensed Matter Physics-- General Techniques in Condensed Matter-- (1987-)
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
ABLATION
ACTINIDE COMPOUNDS
CARBIDES
CARBON
CARBON COMPOUNDS
CHALCOGENIDES
DEPOSITION
DYNAMIC MASS SPECTROMETERS
ELECTRON MICROSCOPY
ELEMENTAL MINERALS
ELEMENTS
EVAPORATION
EXCIMER LASERS
FILMS
GAS LASERS
GRAPHITE
HIGH-TC SUPERCONDUCTORS
IONIZATION
LASERS
MASS SPECTRA
MASS SPECTROMETERS
MEASURING INSTRUMENTS
MICROSCOPY
MINERALS
NONMETALS
OXIDES
OXYGEN COMPOUNDS
PHASE TRANSFORMATIONS
PHOTOIONIZATION
SCANNING ELECTRON MICROSCOPY
SILICON CARBIDES
SILICON COMPOUNDS
SOLID CLUSTERS
SOLIDS
SPECTRA
SPECTROMETERS
SUPERCONDUCTING FILMS
SUPERCONDUCTORS
TIME-OF-FLIGHT MASS SPECTROMETERS
TIME-OF-FLIGHT SPECTROMETERS
URANIUM COMPOUNDS
URANIUM OXIDES