THEORETICAL-STUDY OF ONE-DIMENSIONAL CHAINS OF METAL ATOMS IN NANOTUBES

Using first-principles total-energy pseudopotential calculations, we h ave studied the properties of chains of potassium and aluminum in nano tubes. For BN tubes, there is little interaction between the metal cha ins and the tubes, and the conductivity of these tubes is through carr iers located at the inner part of the tube. In contrast, for small rad ius carbon nanotubes, there are two types of interactions: charge-tran sfer (dominant for alkali atoms) leading to strong ionic cohesion, and hybridization (for multivalent metal atoms) resulting in a smaller co hesion. For Al-atomic chains in carbon tubes, we show that both effect s contribute. Electronic properties related to these confined atomic c hains of metal are analyzed.