Time and Temperature Stability of Magnetization- a Study on Magnetite and Titanomagnetite Prepared by the Glass-Ceramic Method

在Asilomar岩石磁学研讨会(1986年9月16-19日)上一致认为，影响地磁场产生和反转、大陆边缘构造和前寒武纪大陆漂移的下一代古地磁问题，需要我们大幅增加对纯磁铁矿和钛磁铁矿磁化作用的时间和温度影响的知识。发展了一种材料合成技术，即微晶玻璃方法，在非磁性基质材料中制备尺寸从50 nm到100微米的分散良好的单晶。这些样品(以及其他新合成的样品)将被用来研究外加磁场、温度和内应力对热粘性磁化的获得和稳定性的影响。这些实验将揭示，对于我们已经证明用现有理论无法解释其热磁性质的多域样品，通过“双调制”或“后效”现象实现的磁场壁/应力相互作用是重要的。这些结果也将与最好的并可能改进热古强度的方法相关，目前这是一个相当有争议的问题。

At the Asilomar Workshop on Rock Magnetism (September 16-19, 1986) it was unanimously agreed that the next generation of paleomagnetic problems which impact on geomagnetic field generation and reversal, tectonics of continental margins and Precambrian continental drift require a major increase in our knowledge of the effects of time and temperature on the magnetization of pure magnetite and titanomagnetite. A materials synthesis technique, the glass-ceramic method, which produces well dispersed single crystals ranging in size from 50 nm to 100 um in a non-magnetic matrix material has been developed. These samples (and other newly synthesized ones) will be used to study the effects of applied field, temperature and internal stress on the acquisition and stability of thermo-viscous magnetization. The experiments will reveal whether domain wall/stress interaction through "disacommodation" or "aftereffect" phenomenon is important for multidomain samples whose thermomagnetic properties we have shown to be not explicable with existing theories. The results will also be relevant to best and possibly improve thermal paleointensity methods, presently a matter of considerable controversy.