The magnetic properties of Nd2Fe14B (NFB)/transition metal (TM = Fe, Co) multilayer systems are studied on the basis of first-principles density functional calculations. Assuming a collinear spin structure, we optimize the model structure under a variety of crystallographic alignments of the NFB layer, and analyze the mechanism of interface magnetic coupling. Improvements in remanent magnetization compared to that of single NFB are observed in NFB(001)/Fe, NFB(110)/Fe, and NFB(100)/Co. On the other hand, in NFB(100)/Fe, remanence degradation due to the antiparallel magnetization alignment between NFB and Fe layers is observed. In this system, which has the shortest optimized interlayer distance among all considered systems, an itinerant electron magnetism is required around the interface to lower the total energy, and accordingly, antiferromagnetic coupling is preferred. The significant difference in property between NFB(100)/Fe and NFB(100)/Co is attributed to the difference between their interface structures, optimized interlayer distances, and magnetic stiffness of TM layers.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics