Magnetic ground states in nanocuboids of cubic magnetocrystalline anisotropy

Francisco Javier Bonilla (1) , Lise-Marie Lacroix (1) , Thomas Blon (1)

1 LPCNO - Laboratoire de physique et chimie des nano-objets

Flower and easy-axis vortex states are well-known magnetic configurations that can be stabilized in small particles. However, <111> vortex (V<111>), i.e. a vortex state with its core axis along the hard-axis direction, has been recently evidenced as a stable configuration in Fe nanocubes of intermediate sizes in the flower/vortex transition. In this context, we present here extensive micromagnetic simulations to determine the different magnetic ground states in ferromagnetic nanocuboids exhibiting cubic magnetocrystalline anisotropy (MCA). Focusing our study in the single-domain/multidomain size range (10–50 nm), we showed that V<111> is only stable in nanocuboids exhibiting peculiar features, such as a specific size, shape and magnetic environment, contrarily to the classical flower and easy-axis vortex states. Thus, to track experimentally these V<111> states, one should focused on (i) nanocuboids exhibiting a nearly perfect cubic shape (size distorsion <12%) made of (ii) a material which combines a zero or positive MCA and a high saturation magnetization, such as Fe or FeCo; and (iii) a low magnetic field environment, V<111> being only observed in virgin or remanent states.

Mots clés: Flower-vortex transition; Single-domain limit; Hard-axis vortex; Magnetic nanocubes

Domaines: Chimie; Physique [physics]

Francisco Javier Bonilla, Lise-Marie Lacroix, Thomas Blon. Magnetic ground states in nanocuboids of cubic magnetocrystalline anisotropy. Journal of Magnetism and Magnetic Materials, In press, 428, pp.394-400. ⟨hal-01982612⟩