Physical–chemical properties of M@Fe3O4 core@shell nanowires (M = Cu, Co, CoO)

Interest in low dimensional magnetic systems has been growing due to the novel and dramatically differentiated effects of their physical properties, which give them special behaviors and uses in biomedical, environmental and technological fields. In this study we report extensive first-principles calculations on the geometric optimization as well as electronic, magnetic, mechanical and thermal properties of several quasi one-dimensional core/shell nanowires: Cu/Fe3O4, Co/Fe3O4, and CoO/Fe3O4. The main focus lies on the quantum confinement effects as well as on the effect of the interaction between the ferrimagnetic semiconductor shell material (magnetite nanotube) and core compounds with differentiated magnetic behavior such as (i) a ferromagnetic material (Co), (ii) an antiferromagnetic transition metal oxide (CoO) and (iii) a non-magnetic simple metal (Cu). The mechanical properties of the related nanosystems are studied through the effects of axial deformations, and their thermal behavior is evaluated by considering the electronic contribution of each sample to the heat capacity, and some potential technological applications are suggested.