Real-Time Studies of Gallium Adsorption and Desorption Kinetics by Grazing-Incidence Small-Angle X-ray Scattering and X-ray Fluorescence

Journal Article · Tue Jan 01 04:00:00 EST 2008 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.2936969· OSTI ID:1019769

Wang, Y; Ozcan, A; Ludwig, K; Bhattacharyya, A

Gallium adsorption and desorption on c-plane sapphire has been studied by real-time grazing incidence small-angle x-ray scattering and x-ray fluorescence as a function of substrate temperature (680-740 C) and Ga flux. The x-ray techniques monitor the surface morphology evolution and amount of Ga on the surface. During deposition, nanodroplets of liquid Ga are observed to form on the surface and coarsen. The growth of droplet size during continuous deposition follows dynamical scaling, in agreement with expectations from theory and simulations which include deposition-induced droplet coalescence. However, observation of continued droplet distance scale coarsening during desorption points to the necessity of including further physical processes in the modeling. The desorption rate at different substrate temperatures gives the activation energy of Ga desorption as 2.7 eV, comparable to measured activation energies for desorption from Ga droplets on other substrates and to the Ga heat of vaporization.

• Research Organization: Brookhaven National Laboratory (BNL) National Synchrotron Light Source
• Sponsoring Organization: DOE - OFFICE OF SCIENCE
• DOE Contract Number: AC02-98CH10886
• OSTI ID: 1019769
• Report Number(s): BNL--95615-2011-JA
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 10 Vol. 103; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ACTIVATION ENERGY
ADSORPTION
COALESCENCE
DEPOSITION
DESORPTION
FLUORESCENCE
GALLIUM
KINETICS
MONITORS
MORPHOLOGY
SAPPHIRE
SCATTERING
SIMULATION
SUBSTRATES
VAPORIZATION HEAT
national synchrotron light source