Simulations micromagnetic

This chapter investigates how intrinsic and extrinsic properties are affected by nanostructuring. Emphasis is on model calculations and analytical approximations, as contrasted to Chapter 2 by Kashyap et al. which focuses on numerical calculations, and Ch. 4 by Schrefl et al., where emphasis is on micromagnetic models and simulations. Section 2 is devoted to static properties, whereas section 3 is concerned with magnetization dynamics. Finally, section 4 presents a number of case studies. 

Numerical micromagnetics, which may be based either on the finite difference or finite element method, resolve the local arrangement of the magnetization which arises from the interaction between intrinsic magnetic properties such as the magnetocrystalline anisotropy and the physical and chemical microstructure of the material. The numerical solution of the equation of motion also provides information on how the magnetization evolves in time. The time and space resolution of numerical micromagnetic simulations is in the order of nanometers and nanoseconds, respectively. 

Dynamic micromagnetics simulations show that shape, size, and damping constant significantly influence the switching behavior of thin film elements. The magnetization reversal of submicron NiFe elements was found to be a two stage process. At first, the magnetization rotates almost in plane towards... 

Figure 17. Micromagnetic simulations for a SD and MD state of CoNi/Pt dots with 30 nm thickness (left) and (right) the AASA process for a 2.5 inch disk.

Gao KZ, Bertram HN (2002) 3-D micromagnetic simulation of write field rise time in perpendicular recording. IEEE Trans Magn 38 2063-2065... 

All these sizes can be treated as a unit of magnetic moment in micromagnetic calculations, for example, see Fukunaga and Kanai (1998). The interactions among them can also be evaluated in the simulations. 

Therefore, the most obvious ability of the micromagnetic approaches appears to be in the simulation of systems in which complex interactions between finite regions strongly... 

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