Morphology transitions in three-dimensional domain growth with Gaussian random fields

Article

关键词: FLUID INVASION;    POROUS-MEDIA;    DEPINNING TRANSITION;    DISORDERED-SYSTEMS;    QUENCHED DISORDER;    DRIVEN INTERFACES;    2 DIMENSIONS;    ISING-MODEL;    DYNAMICS;    MOTION;   

DOI  :  10.1103/PhysRevB.62.5771

来源: SCIE

【 摘 要 】

We study the morphology of magnetic domain growth in disordered three-dimensional magnets. The disordered magnetic material is described within the random-field Ising model with a Gaussian distribution of local fields with width Delta. Growth is driven by a uniform applied magnetic field, whose value is kept equal to the critical value H-c(Delta) for the onset of steady motion. Two growth regimes are clearly identified. For low Delta the growing domain is compact, with a self-affine external interface. For large Delta a self-similar percolationlike morphology is obtained. A multicritical point at [Delta(c),H-c(Delta(c))] separates the two types of growth. We extract the critical exponents near Delta(c) using finite-size scaling of different morphological attributes of the external domain interface. We conjecture that Delta(c) corresponds to the maximum in H-c(Delta).

【 授权许可】

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