Ising nanowires with simple core–shell structure; Their characteristic phenomena

• Ferrimagnetic behavior in the system with a negative exchange interaction.
• A characteristic behavior of saturation magnetizations.
• Common phase diagrams for nanowires.

The phase diagrams and magnetizations of Ising nanowires with simple core–shell structure are investigated by the use of the effective field theory with correlations. A lot of characteristic behaviors observed in ferromagnetic and ferrimagnetic materials as well as novel phenomena have been obtained, although one section of the system is consisted of one spin-1/2 surface shell atom and one spin-1/2 core atom and they are coupled with a positive or a negative shell–core exchange interaction.