Bistability, softening, and quenching of magnetic moments in Ni-filled carbon nanotubes

The authors apply first-principles calculations to investigate the interplay between structural, electronic, and magnetic properties of nanostructures composed of narrow nanotubes filled with metallic nanowires. The focus is on the structural and magnetic responses of Ni-filled nanotubes upon radial compression. Interestingly, metastable flattened structures are identified, in which radially deformed nanotubes are stabilized by the interactions with the encapsulated wire. Moreover, our results indicate a quenching of the magnetic moment of the wire upon compression, as a result of the transfer of charge from the $s$ to the $d$ orbitals of the atoms in the wire.