Structural, electronic and magnetic properties of the 3d transition metal atoms adsorbed on boron nitride nanotubes

Adsorption configurations for a series of transition metal (TM) 3d atoms adsorbed on the zigzag (8, 0) BNNT at five different sites have been investigated using the first-principles PAW potential within DFT under GGA. The most stable adsorption sites are different for different TM atoms. Partially filled 3d metals V, Cr and Mn can bind strongly with zigzag (8, 0) BNNT, and Sc, Ti, Co and Ni can be chemically adsorbed on the (8, 0) BNNT. The binding between the Fe or Cu atom and the BNNT is only marginal. One unusual case is Zn. Its zero binding energy independent of the adsorption sites implies it can only physically adsorbed on the BNNT mainly stemmed from the van de Waals interaction. Electronic structure analyses show that: (1) for each TM atom adsorbed at five different sites, the total DOS curves of both majority and minority spins make a slightly relative shift along the energy axis, and for each site the total DOS of the minority spin shifts slightly in high energy direction with respect to that of the majority spin lead to a exchange splitting, except fully filled 3d metals Cu and Zn; (2) total DOS curves of both the majority and minority spins for the adsorbed systems shift to the lower energy region compared with that of the pristine (8, 0) BNNT. And the smaller 3d electrons number of the TM atom, the larger shift to the lower energy region of its DOS curves; (3) for V-, Mn- and Fe-adsorbed (8, 0) BNNT, only one type of electrons (either majority spin or minority spin) passes through the Fermi level implies these adsorbed systems are all half-metals.