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Liquid-cell Transmission Electron Microscopy for Tracking Self-assembly of Nanoparticles
Published on: October 16, 2017
Spontaneous ordering of oxide nanostructures
1Department of Materials and Nuclear Engineering, Department of Physics, University of Maryland, College Park, MD 20742, USA. Flat Panel Display Division, Motorola Inc., 7700 South River Parkway, Tempe, AZ 85284, USA.
Science (New York, N.Y.)
|March 24, 2000
Summary
Uniform arrays of palladium oxide "tips" spontaneously form on thin palladium films during oxidation. Film thickness and processing conditions influence tip size and density, suggesting potential for field emission applications.
Area of Science:
- Materials Science
- Surface Science
- Nanotechnology
Background:
- Palladium (Pd) thin films are crucial in various electronic and catalytic applications.
- Controlling nanostructure formation on thin films is essential for advanced material properties.
Purpose of the Study:
- To investigate the spontaneous formation of nanostructures during palladium thin film oxidation.
- To understand the relationship between film properties, processing conditions, and nanostructure morphology.
- To explore the potential applications of these nanostructures.
Main Methods:
- Oxidation of palladium thin films with varying thicknesses (40-200 nm).
- Characterization of the resulting nanostructures (tips/hillocks).
- Analysis of the influence of film thickness, granularity, annealing, and oxidation conditions.
- Measurement of photoelectron emission properties.
Main Results:
- Uniform arrays of conical palladium oxide tips formed spontaneously.
- Tip height increased from 0.5 to 1.2 µm with increasing film thickness.
- Tip density decreased from 55 x 10^6 to 12 x 10^6 cm^-2 as thickness increased.
- Broader height distribution observed with thicker films.
Conclusions:
- Palladium film thickness and oxidation conditions dictate the formation and morphology of oxide tips.
- The observed tips exhibit enhanced photoelectron emission.
- These palladium oxide tips show promise for field emission device applications.
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