Micromagnetism Applied to Magnetic Nanostructures

This chapter summarizes the basic concepts of micromagnetic theory, used extensively for modeling ferromagnetic nanostructured systems, including thin films, wires, and nanopillars. In the first section, the assumptions used in micromagnetism are listed and the ingredients needed for the general equations governing the magnetically stable state and the magnetization dynamics (interactions, energies, fields) are introduced. The second section illustrates how micromagnetic theory is used to describe the magnetic behavior of nanosize magnetic samples, in particular the differences between single‐domain and multidomain states. The third part shows the differences between the macrospin and micromagnetic models in the study of spin‐transfer torque magnetic random‐access memory (STT‐MRAM) with in‐plane magnetized layers. The role of interlayer dipolar coupling in the magnetization reversal process in STT‐MRAM is discussed in the last part
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