A molecular dynamics study on the vibrational behavior of perfect and defective hybrid carbon boron-nitride heteronanotubes

Abstract

In this paper, the free vibration of hybrid carbon boron-nitride heteronanotubes (CBNNTs) is analyzed through molecular dynamics (MD) simulations. In the vibration analysis, various CBNNTs (Cx ∣ (BN)y and C-BN models) according to two geometrical arrangements of constituent segments are considered. By introducing vacancy defects in nanotubes, the influence of defects on the vibrational response is studied in terms of the weight percentage and distribution pattern. The highest vibration frequency is reported and CBNNTs' results are compared with those of carbon nanotubes (CNTs) and boron-nitride nanotubes (BNNTs). It is observed that CBNNTs possess natural frequencies which lie between the values for CNTs and BNNTs. The natural frequency is found to be reduced by increasing the defect percentage. At each defect percentage, the defective C-(BN) model I and C1.5 ∣ (BN)1.5 experience almost the same natural frequency in both distribution patterns. Vibration frequencies of defective C-(BN) model II and C4.5 ∣ (BN)4.5 are nearly close together at a defined percentage of defects. Despite the minor differences between natural frequencies in either distribution pattern, regularly defected CNTs tend to have a bit higher frequency than randomly defected CNTs, however, the results are opposite in the regularly and randomly defected BNNTs. Moreover, the C-(BN) model II vibrates at a higher natural frequency than that of the C-(BN) model I. It is found that the vibrational behavior of the C-(BN) model I is mostly affected by the BN segment than the C segment. Further, the natural frequency's drop in the defected C1.5 ∣ (BN)4.5 is found to be more significant than other CBNNTs by rising the defect percentage. C-(BN) model I and defective C-(BN) model I experience higher deformations in comparison with the Cx ∣ (BN)y configurations when vibrating at their natural frequency.