Twinning is one of the most popular planar defects in nanocrystals, and it is frequently observed in face-centered cubic (fcc) structured metallic nanocrystals. In this study, copper, silver, and gold nanowires with diameters of 30-50 nm were prepared by electrochemical deposition in "track-etched" polycarbonate membranes. High-resolution transmission electron microscopy (HRTEM) and electron diffraction were used to study the microstructure of the nanowires. Microtwins were observed to be dependent on growth orientation in the single-crystal metal (copper, silver, and gold) nanowires. In single-crystal nanowires with a  growth orientation, both primary (111)[112̄] and secondary (1̄1̄1) twins were observed, whereas in the wires with a [112̄] growth orientation, lengthwise twins and stacking faults were the dominant features. No twinning was observed in nanowires that grew along the  and  directions. The crystallography of the twins was characterized by HRTEM and electron microdiffraction. The twinning mechanism (nucleation and growth) is discussed in relation to a two-dimensional (2D) nucleation and growth mechanism for the single-crystal nanowires.
All Science Journal Classification (ASJC) codes
- Physical and Theoretical Chemistry
- Surfaces, Coatings and Films
- Materials Chemistry