Size-Dependent Spin Structures in Iron Nanoparticles

A. Fraile Rodríguez, A. Kleibert, J. Bansmann, A. Voitkans, L. J. Heyderman, F. Nolting
2010 Physical Review Letters  
Using photoemission electron microscopy, we study the magnetization orientation in single 5-25 nm iron particles coupled to a ferromagnetic cobalt support. We find a noncollinear alignment between the particle and substrate magnetization above a particle size of $6 nm and a parallel alignment for smaller sizes. Numerical calculations reveal a transition from an exchange-dominated to an anisotropy-dominated regime on increasing the particle height: the smaller particles are in a single-domain
more » ... linear state while larger particles exhibit a spin-spiral magnetic structure determined by the magnetic anisotropy energy.
doi:10.1103/physrevlett.104.127201 pmid:20366559 fatcat:dbsvvmxygbddroplpbf2h3thi4