Room temperature ferromagnetism in Cu–Gd co-doped GaN nanowires: A first-principles study

Publication date: Available online 11 September 2018Source: Physics Letters AAuthor(s): Ruikuan Xie, Huaizhong Xing, Yijie Zeng, Yan Huang, Aijiang Lu, Xiaoshuang ChenAbstractThe electronic structure and room temperature ferromagnetism of wurtzite Cu–Gd co-doped GaN nanowires have been investigated by means of the first-principles calculations within the density functional theory, including the on-site Coulomb energy U. The magnetic coupling between Gd atoms in the Gd-doped GaN nanowire is paramagnetic instead of ferromagnetic (FM) as in the bulk structure. After replacing Ga with Cu atom we find a stable FM coupling between Gd magnetic moments in this p-type system. P-d coupling between Cu-3d and N-2p states pushes N-2p states up to Fermi level due to the existence of hole states introduced by Cu dopants. While the p-d coupling between host N-2p and Gd-5d states near Fermi level stabilizes a FM phase of Gd magnetic moments. Furthermore, we get a FM state above room temperature by increasing the holes concentration.

Source: Physics Letters A - September 11, 2018 Category: Physics Source Type: research