Magnetization of carbon-doped MgO nanotubes

Using local spin-density-functional formalism, we study the occurrence of spin polarization in magnesium oxide nanotubes doped with carbon impurities. We find that carbon impurity acquires a magnetization caused by the 2p states partly filled and placed in forbidden gap of a MgO tube. According to our estimations, for carbon impurity replacing oxygen inside the MgO tube wall, the spin magnetization (at about 2 mu(B) per cell) is found. The results are used in discussion of the new approach to the engineering of magnetic nanotubes, namely, the magnetization of nonmagnetic tubes induced by nonmagnetic impurities.