単磁区粒子の保磁力値の粒子径依存 : マイクロ・マグネティクス計算に基づく検証

概要

論文の詳細を見る
A consideration has been made for coersivity of magnetic single-domain particles in the magnetization reversal process, where the uniaxial magneto-crystalline anisotropy plays a role for the coercivity. The particle-size region argued in this article is for the smaller particle sizes in single-domain particle states, that is, the various particle sizes less than a single-domain critical size by assuming no involvement of superparamagnetism. Magnetic hysteresis loops have been calculated for a hypothetical iron-based ferromagnetic material by a computer simulation based on Landau-Lifshitz-Gilbert equation. A particle shape modeled is a cylinder, in which a variable particle size of 30〜100nm in diameter with a fixed height of 30nm for each is considered. The results indicate the higher coercivity for the smaller particle sizes in a single-domain state, and suggest that the magnetization reversal mode acting in a single-domain particle can be variable with the particle size even of nominal single-domain particles.
石巻専修大学の論文