A generalized theory of thermoremanence, covering the transition from single domain to multi-domain magnetic grains
A generalized theory of thermoremanence, covering the transition from single domain to multi-domain magnetic grains
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DOI：
10.1080/14786436208213853
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发表时间：
1962-11
影响因子：
1.6
通讯作者：
F. D. Stacey
中科院分区：
文献类型：
--
作者：
F. D. Stacey
摘要单晶磁性颗粒具有显著的永久磁矩(伪单磁畴)，这是由于其磁畴壁位置的巴克豪森离散性所致。这些力矩与颗粒直径的3/2次方成正比，并与直径在0.03μ到约5μ之间的颗粒的低场热磁有关。较小的颗粒是真正的单域，较大的颗粒表现为真正的多域，具有早期理论准确描述的性质。温度对颗粒尺寸的影响图显示，在0.3Trm处有一个很强的极大值，此时μ的强度是大颗粒的40倍。在退磁条件下，直径达数百微米的颗粒的永久力矩变得重要。它们在极小的杂散场中获得饱和排列，使可观察到的样品磁化程度与磁场完全不成比例，而且即使在没有杂散场的情况下，它们也可能相互作用而导致相互排列。这被认为是..。
Abstract Single crystal magnetic grains are found to have appreciable permanent (pseudo-single domain) moments by virtue of the Barkhausen discreteness in the positions of their domain walls. These moments are proportional to the 3/2 power of grain diameter and are responsible for the low-field thermoremanence of grains with diameters between 0.03 μ and approximately 5 μ. Smaller grains are true single domains, larger ones behave as true multi-domains with properties accurately described by an earlier theory. A graph of thermoremanence against grain size shows a strong maximum at 0.3 μ, at which TRM is 40 times as strong as for large grains. Under demagnetizing conditions the permanent moments of grains up to several hundred microns across become important. They acquire saturation alignment in extremely small stray fields, giving observable specimen magnetizations quite out of proportion to the fields, and may also interact to cause mutual alignment even in the absence of stray fields. This is considered ...