Melting, growth, and faceting of lead precipitates in aluminum
Abstract
Aluminum single crystals cut in the <111> direction were implanted with 2×1020 m-2 Pb+ ions at 75 or 150 keV. The implanted insoluble lead precipitated as epitaxially oriented crystallites in the aluminum matrix. The precipitates were studied by x-ray diffraction at Riso, DESY, and Brookhaven National Laboratory, and showed large superheating as well as supercooling during repeated heating cycles. The as-implanted precipitates had a characteristic size of ~140 Å, which grew to 210-260 Å during repeated heating cycles. A detailed annealing study shows that the growth rate of the precipitates changes discontinuously at the onset of melting. This shows that significant precipitate growth takes place by coalescence. The diffracted x-ray intensities showed characteristic truncation rods (streaks), indicating that the solid precipitates were octahedra limited by \{111\} planes and truncated at the corners by \{100\} facets.
- Publication:
-
Physical Review B
- Pub Date:
- February 1992
- DOI:
- 10.1103/PhysRevB.45.2628
- Bibcode:
- 1992PhRvB..45.2628G
- Keywords:
-
- 64.70.Dv;
- 61.50.Cj;
- 68.35.Bs;
- 61.10.-i;
- Solid-liquid transitions;
- Structure of clean surfaces;
- X-ray diffraction and scattering