Abstract
Electrically conducting nanocomposites of bismuth metal and insulating ceramic phases of SiO2 and MgO were generated via high-energy ball milling for 24 h using zirconia milling media. The resulting nanocomposites contain Bi nanoparticles with sizes down to 5 nm in diameter. The morphology is a strong function of the oxide phase: specifically, the Bi appears to wet MgO while it forms spherical nanoparticles on the SiO2. X-ray diffraction measurements indicate a nominal bismuth grain size of 50 nm, and peak fitting to a simple bidisperse model yields a mixture of approximately 57% bulk bismuth and 43% 27 nm diameter crystallites. Nanoparticles as small as 5 nm are observed in transmission electron microscopy (TEM), but may not constitute a significant volume fraction of the sample. Differential scanning calorimetry reveals, dramatic broadening in the temperatures over which melting and freezing occur and a surprising persistence of nanostructure after thermal cycling above the melting point of the Bi phase.
Original language | English (US) |
---|---|
Pages (from-to) | 795-799 |
Number of pages | 5 |
Journal | Advanced Functional Materials |
Volume | 13 |
Issue number | 10 |
DOIs | |
State | Published - Oct 2003 |
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Biomaterials
- General Chemistry
- General Materials Science
- Condensed Matter Physics
- Electrochemistry