Multiscale Modeling of Magnetic Nanoparticles

Project Summary

The aim of the project is to develop a systematic way of extracting effective parameters for magnetic nanoparticles in order to simulate reliably the magnetic behavior of their dense (interacting) assemblies. To fulfill this aim atomic scale simulations of the magnetic properties of isolated nanoparticles are performed within the classical Heisenberg Hamiltonian taking in addition into account single-ion anisotropy terms and anisotropic exchange coupling, whenever this is dictated by the properties of the material under investigation. Effective parameters (magnetic moment, anisotropy energy density) are extracted by Constrained Monte Carlo (CMC) techniques based on Lagrange Multipliers, Direct Elimination and related methods. The role of temperature, applied field and interparticle interactions on the effective parameters is thoroughly studied. Single-phase, composite and hybrid nanoparticles are under investigation. Finally, the effective parameters are used to model interacting assemblies of nanoparticles with various morphologies.