Switching Behaviour of Magnetic Particles with Dipolar Interaction
XU Chen1,2, HUI Pak-Ming3, CHOW Chow-Wang3, LI Zhen-Ya2
1Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093
2Department of Physics, Suzhou University, Suzhou 215006
3Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
Switching Behaviour of Magnetic Particles with Dipolar Interaction
1Laboratory of Solid State Microstructures, Nanjing University, Nanjing 210093
2Department of Physics, Suzhou University, Suzhou 215006
3Department of Physics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong
Abstract： We study the switching in the magnetic moments of interacting magnetic particles. The dynamics of the magnetic moments is governed by a coupled set of Landau--Lifshitz--Gilbert equations. The magnetic particles are assumed to be spherical in shape, single domain, and have uniaxial anisotropy. Effects of dipolar interaction between the particles, anisotropy energy, an applied switching field with finite spatial extent and a small bias field are considered. When the separation between the particles is small, the dipolar field is significant and it affects the reversal of the magnetic moments. The final configuration attained depends sensitively on the decaying length of the switching field, the inter-particle separation, and the initial configuration. A bias field tends to suppress the effects of a spatially decaying switching field and dipolar interaction between neighbouring particles.
2005, Vol. 22 
