Dipolar ferromagnetism in three-dimensional superlattices of nanoparticles

Abstract

A series of atomistic finite temperature simulations on a model of an FCC lattice of maghemite nanoparticles using the stochastic Landau-Lifshitz-Gilbert (sLLG) equation are presented. The model exhibits a ferromagnetic transition that is in good agreement with theoretical expectations. The simulations also reveal an orientational disorder in the orientational order parameter for $T<0.5T_c$ due to pinning of the surface domain walls of the nanoparticles by surface vacancies. The extent of the competition between surface pinning and dipolar interactions provides support for the conjecture that recent measurements on systems of FCC superlattices of iron-oxide nanoparticles provide evidence for dipolar ferromagnetism is discussed.

References in corpus (5)

• Magnetic Monopoles in Spin Ice
• Forward Flux Sampling for rare event simulations
• Magnetic properties of dense nanoparticle arrays with core/shell morphology
• Micromagnetic simulations of interacting dipoles on a fcc lattice: Application to nanoparticle assemblies
• Atomic level micromagnetic model of recording media switching at elevated temperatures

Cited by in corpus (4)

• Phase diagram of a three-dimensional dipolar model on a FCC lattice
• Triangular array of iron-oxide nanoparticles: A simulation study of intra- and inter-particle magnetism
• Long-range order in arrays of composite and monolithic magneto-toroidal moments
• Spontaneous orbital magnetization of mesoscopic dipole dimers