The formation of symmetric SiC bi-nanowires with a Y-shaped junction

Transmission electron microscopy was used to investigate the formation mechanism of SiC bi-nanowires (BNW) with a Y-shaped junction. Different from the previously reported growth mechanisms, our study suggests that when two individual nanowires that are growing through the vapor-liquid-solid mechanism meet with a proper angle, they will merge and form a straight and symmetric BNW with its two side-branches maintaining their original crystallographic orientations and sharing the same crystallographic growth direction, which can be < 110 >, < 112 > or < 113 >, depending on the meeting angle between the two initial nanowires. According to our observations, a growth model of SiC BNWs with a Y-shaped junction was proposed. The radii and the microstructure of the BNWs are controlled to a certain extent by the meeting angle and the radii of the two SiC single NWs.