Nano Segregation Effects on Nano Magnetic Properties in Multi-Layer Thin Films

摘要

nanocrystalline systems attract more and more interest due to their applications on chemical catalysis and magnetic recording. Magnetic nanostructures have become centre of great interest in the scientific community and in industry as the core technologies behind magnetic recording devices. The magnetic properties of thin films are strongly influenced by their structure. Small changes in the way a thin film is produced often give rise to large changes in some of the magnetic properties of the thin film. The presence of (nanostructures) non-magnetic (or less magnetic) inhibits or hampers exchange interaction between adjacent grains, and hence increases the dipolar character of the magnetic interactions between grains. This is best understood by observing how the microstructure of the film changes with processing and then correlating the microstructure directly with the properties of the thin film. Experiments shows that segregation of nonmagnetic elements (like Cr or Ta) in co enhances the magnetic property of thin films (such as CoCrTa). The saturation magnetization Ms and the Curie temperature of the alloy are substantially reduced. From the signal point of view, adding non-magnetic elements into Co poses a disadvantage, that is the substantial reduction of signal-to-noise ratio due to the drop in Ms.