Kooi B J, Vystavel T, De Hosson J T
Department of Applied Physics, Materials Science Center, The Netherlands Institute for Metals Research, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
J Nanosci Nanotechnol. 2001 Mar;1(1):65-73. doi: 10.1166/jnn.2001.016.
This article aims to make a connection between the microstructures of various nanostructured alloys and giant magnetoresistive (GMR) properties. The GMR behavior of nanoclusters embedded in a nonmagnetic matrix differs considerably from an alloy with the content of a magnetic phase above the percolation threshold; that is to say, an increase of GMR effect upon going from 300 to 10 K for the former and a decrease of the GMR effect for the latter. The following materials systems were examined with high-resolution transmission electron microscopy and magnetoelectrical resistance measurements: magnetic Co and CoFe nanoclusters in a Au matrix, NiFe clusters in a Cu matrix, and NiFe/Cu spinodal decomposition waves with interconnection of the magnetic phase. After annealing (> or = 300 degrees C), Co particles in Au become semi- or incoherent, whereas under other conditions and in all other systems, the interfaces remain coherent. This state of coherency at the interface between magnetic particles and a nonmagnetic matrix turned out to have a detectable influence on the GMR behavior.
本文旨在建立各种纳米结构合金的微观结构与巨磁阻（GMR）特性之间的联系。嵌入非磁性基体中的纳米团簇的GMR行为与磁性相含量高于渗流阈值的合金有很大不同；也就是说，对于前者，从300 K到10 K时GMR效应增加，而对于后者，GMR效应降低。通过高分辨率透射电子显微镜和磁电阻测量研究了以下材料体系：Au基体中的磁性Co和CoFe纳米团簇、Cu基体中的NiFe团簇以及具有磁性相互连的NiFe/Cu旋节线分解波。退火后（≥300℃），Au中的Co颗粒变为半相干或非相干，而在其他条件下以及在所有其他体系中，界面保持相干。事实证明，磁性颗粒与非磁性基体之间界面的这种相干状态对GMR行为有可检测的影响。
