A stable 4f half-metallic ferromagnetism Eu4O3N predicted from GGA plus U calculations

Objective: Half-metallic ferromagnetism plays a major role in high-performance spintronic applications due to its 100% spin-polarization. So, it is very necessary to search better half-metallic ferromagnets with large magnetic moment and being compatible with current semiconductor technology. Methods: We study cubic Eu4O3N on the basis of state-of-the-art first-principles calculations by using generalized gradient approximation plus U method. Results: It is found that the Eu4O3N is a half-metallic ferromagnet with a half-metallic gap of 376 meV and the large Eu ion magnetic moment up to about 7 mu B. The structural and ferromagnetic stability are proved by mechanical stability criterion and magnetic energy differences, respectively. The half-metallic properties are also stable against the isotropic strain, volume-conservative tetragonal strain and rhombohedral distortion. For the choice of U between 4 and 8 eV, the Eu4O3N still is half-metallic ferromagnet. Conclusion: This provides a new idea for searching new half-metallic ferromagnetism by f electrons. Practical implications: lf the Eu4O3N was experimentally synthesized with half-metallic properties, it should be used to design high-performance spintronic devices. (C) 2015 Elsevier B.V. All rights reserved