Determination of precession and dissipation parameters in micromagnetism
[摘要] The precession beta and the dissipation parameter alpha of a ferromagnetic material can be considered microscopically space dependent. Their space distribution is difficult to obtain by direct measurements. In this article we consider an inverse problem, where we aim at recovering alpha and beta from space measurements of the magnetization. The evolution of the magnetization in micromagnetism is governed by the Landau-Lifshitz (LL) equation. We first study the sensitivity of the LL equation. We derive the existence, uniqueness and stability results for the LL equation and the corresponding sensitivity equations. On the basis of the results we analyze the inverse problem. We employ the energy method and we minimize the underlying cost functional by means of the steepest descent method. We derive a convergence result for the proposed algorithm. The presented numerical examples support the theoretical results. (C) 2009 Elsevier B.V. All rights reserved.
[发布日期] 2010-08-01 [发布机构]
[效力级别] Proceedings Paper [学科分类]
[关键词] Micromagnetism;Parameter estimation;Inverse problems;Sensitivity analysis [时效性]
