Magnetic relaxation and dipole-coupling-induced magnetization in nanostructured thin films during growth: A cluster Monte Carlo study

Article

关键词: INTERPARTICLE INTERACTIONS;    SYSTEMS;    DYNAMICS;    MOMENTS;    ISLANDS;    MODELS;   

DOI  :  10.1103/PhysRevB.68.174414

来源: SCIE

【 摘 要 】

For growing inhomogeneous thin films with an island nanostructure similar to that observed in experiment we determine the nonequilibrium and the equilibrium remanent magnetization. The single-island magnetic anisotropy, the dipole coupling, and the exchange interaction between magnetic islands are taken into account within a micromagnetic model. A cluster Monte Carlo method is developed which includes coherent magnetization changes of connected islands. This causes a fast relaxation towards equilibrium for irregularly connected systems. We analyze the transition from dipole coupled islands at low coverages to a strongly connected ferromagnetic film at high coverages during film growth. For coverages below the percolation threshold the dipole interaction induces a collective magnetic order with ordering temperatures of 1-10 K for the assumed model parameters. Anisotropy causes blocking temperatures of 10-100 K and thus pronounced nonequilibrium effects. The dipole coupling leads to a somewhat slower magnetic relaxation.

【 授权许可】

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