Formation of Nano-structure Material Using Chaotic Theory and its Physical Properties

据报道，通过反复挤压和轧制可以形成Fe-Ag纳米层状材料；粉末和箔片的反复塑性变形。对反复轧制后的试样进行了巨磁电阻（GMR）观察。仅在每层厚度小于1nm的多层材料中报道过GMR效应。而反复轧制的试样，即使厚度在50nm左右，也表现出GMR效应。本研究采用磁控溅射法制备了层厚在10nm ~ 100nm之间的多层样品。在这些材料中，只有10nm样品在77K时显示出0.15%的GMR。70nm样品在77K时GMR为4.5%。由于反复轧制后的样品层厚分布，导致溅射后的多层样品不均匀。各层厚度采用重复轧制试样测得的数值进行模拟。这个样品显示GMR在77K时为1.5%。因此，均匀多层样品的GMR大于混沌多层样品的GMR。

It is reported that the formation of Fe-Ag nano-layred material can be produced by repeated pressing and rolling ; the repeated plastic deformation of powder and foil. The specimen producedby the repeated rolling is observed the giant magneto-resistance (GMR). The GMR effect has been only reported in the multilayr material the each layr thickness of which is less than 1nm. While the specimen produced by the repeated rolling shows GMR effect, even if the thickness is about 50nm.In this research, the multilayr samples whose layr thickness from 10nm to 100nm were produced by magnetron sputtering. In these material, only 10nm sample shows GMR,0.15% at 77K.While the 70nm sample produced by the repeatedrolling shows GMR,4.5% at 77K.Since the samples produced by the repeated rolling have the distributed layr thickness, The inhomogeneous multilayr sample produced by sputtering is produced. Each layr thickness was simulated by the value which was measured in the repeated rolling sample. This sample shows GMR,1.5% at 77K.Consequently, GMR of homogeneous multilayr sample is larger than that of chaotic multilayr sample.