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

在阿西洛马岩石磁学研讨会上（1986年9月16日至19日），人们一致认为下一代古地磁问题会影响地磁场的产生和反转，大陆边缘构造学和前寒武纪大陆漂移学要求我们对时间和温度对纯磁铁矿和钛磁铁矿磁化的影响的认识有很大的提高。在非磁性基体材料中制备出粒径在50 nm ~ 100 um之间分散良好的单晶的玻璃陶瓷合成技术已经被开发出来。这些样品（以及其他新合成的样品）将用于研究外加磁场、温度和内应力对热粘性磁化的获取和稳定性的影响。实验将揭示通过“失调”或“后效”现象的畴壁/应力相互作用对多畴样品是否重要，我们已经证明这些样品的热磁性不能用现有理论解释。研究结果也将有助于改进古热强度方法，这是目前争议很大的问题。

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.