吉林陨石中铁镍合金的磁学性质  

Magnetic properties of iron-nickel alloys in meteorites:A case study of the Jilin chondrite

作　　者：纪新林[1,2] 潘永信[1] 

机构地区：[1]中国科学院地质与地球物理研究所地球深部研究重点实验室,北京100029 [2]中国科学院研究生院,北京100049

出　　处：《地球物理学报》2012年第6期1973-1979,共7页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(40874032);创新群体项目(40821091)资助

摘　　要：铁镍合金是陨石中重要的磁性物质,其中铁纹石、镍纹石和四方镍纹石是球粒陨石中的主要铁镍合金.然而,迄今针对陨石中铁镍合金的磁学性质研究仍非常缺乏.本文研究了吉林陨石中的铁纹石、四方镍纹石、以及陨硫铁的磁学特征.实验表明,镍含量为6%～7%的铁纹石是该陨石中最主要的铁镍合金物质,它具有低矫顽力和高的热稳定性,居里温度～750℃.镍含量为～48%的四方镍纹石具有高矫顽力和高的热稳定性,居里温度～565℃,它是剩磁的主要载体.陨硫铁在室温为反铁磁性,不具有载剩磁能力,在60K左右存在一个低温转换,在氩气中加热较稳定而在空气中加热被氧化转化为磁铁矿.这些研究结果为鉴定球粒陨石中的磁性物质提供了依据.Iron-nickel alloys such as kamaeite, taenite and tetrataenite are the most important magnetic materials in chondrites meteorites. In this study we studied the Jilin chondrite and found that kamacite containing 6%- 7% Ni has lower coercivity and a Curie temperature （To） of 750℃; tetrataenite containing -48% Ni has higher coercivity and a Tc of 565 ℃. Signals of magnetization and magnetic susceptibility are carried by the former, but remanence is carried by the latter. Troilite （FeS） is antiferromagnetic at room-temperature and thus has no contribution to remanence, but it has a magnetic transition at - 60 K. Troilite is rather thermally stable as heating in argon, while it is oxidized and transformed to magnetite when heating in air. These results provide useful information in regard to magnetic properties of chondrite containing ironnickel alloys.

关 键 词：吉林陨石 铁纹石 四方镍纹石 陨硫铁 

分 类 号：P318[天文地球—固体地球物理学]