A generalized theory of thermoremanence, covering the transition from single domain to multi-domain magnetic grains

摘要: Abstract Single crystal magnetic grains are found to have appreciable permanent (pseudo-single domain) moments by virtue of the Barkhausen discreteness in positions their domain walls. These proportional 3/2 power grain diameter and responsible for low-field thermoremanence with diameters between 0.03 μ approximately 5 μ. Smaller true single domains, larger ones behave as multi-domains properties accurately described an earlier theory. A graph against size shows a strong maximum at 0.3 μ, which TRM is 40 times large grains. Under demagnetizing conditions up several hundred microns across become important. They acquire saturation alignment extremely small stray fields, giving observable specimen magnetizations quite out proportion may also interact cause mutual even absence fields. This considered ...