High temperature shrinking process. (a) TEM micrograph of ~270 nm diameter nanopore before shrinking. (b) TEM micrograph of nanopore after 4 min of thermal shrinking at 1250°C. The pore closed in just 4 min due to high shrinkage rate. The shrinking rate was about 70 nm/min.
Asghar et al. Nanoscale Research Letters 2011 6:372 doi:10.1186/1556-276X-6-372