Chemico-Viscous Remanent Magnetization in the Fe3O4-yFe2O3 System
Chemico-Viscous Remanent Magnetization in the Fe3O4-yFe2O3 System
复制标题
Fe3O4-yFe2O3 系统中的化学粘性剩磁
DOI：
10.1126/science.243.4894.1043
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发表时间：
1989
期刊：
影响因子：
56.9
通讯作者：
D. Dunlop
中科院分区：
文献类型：
--
作者：
�ZDEN �ZDEMIR;D. Dunlop
单畴尺寸磁铁矿（Fe_3 O_4）在50微特斯拉磁场中，在1000 ~ 6560 ℃的13个温度下氧化成磁赤铁矿（γ Fe_2 O_3）时，获得的化学还原磁化强度（CRM）与未氧化磁铁矿在相同磁场和温度条件下获得的粘性还原磁化强度（VRM）相似。氧化相和未氧化相的剩磁也具有类似的抗退磁性。这些相似之处意味着，剩磁的氧化材料是一个化学粘性剩磁磁化（CVRM）具有一些经典的增长CRM和热激活VRM的特性。在低温下，在部分氧化的晶粒，VRM的磁铁矿核心和磁赤铁矿表面层的生长CRM贡献约相等的CVRM。在居里点附近，CVRM的强度增加到霍普金森型峰。高温CVRM比冷却通过居里点产生的热释磁磁化（TRM）更耐退磁。
The chemical remanent magnetization (CRM) acquired when single-domain size magnetite (Fe304) oxidizes to maghemite (γFe2O3) in a 50-microtesla field at a series of 13 temperatures from 1000 to 6560C is of similar intensity to viscous remanent magnetization (VRM) acquired under the same field and temperature conditions by unoxidized magnetite. The remanences of the oxidized and unoxidized phases also have similar resistances to demagnetization. These similarities imply that the remanence of the oxidized material is a chemico-viscous remanent magnetization (CVRM) having some of the characteristics of both classic growth CRM and thermally activated VRM. At low temperatures in partially oxidized grains, VRM of the magnetite core and growth CRM of the maghemite surface layer contribute about equally to CVRM. Near the Curie point, intensity of CVRM increases to a Hopkinson-type peak. High-temperature CVRM is more resistant to demagnetization than the thermoremanent magnetization (TRM) produced from cooling through the Curie point.