Over 1.0Â mm-long boron nitride nanotubes

Over 1.0 mm boron nitride nanotubes (BNNTs) were successfully synthesized by an optimized ball milling and annealing method. Such long BNNTs enable a reliable single tube configuration for electrical property characterization and consequently the resistivity of the long BNNTs is determined to be 7.1 ± 0.9 × 104 Ω cm.