Magnetization compensation point

The rest of this chapter will be focused on R/T multilayers with thin layers where the interfacial magnetism plays a major role. Many of the outstanding properties, such as large PMA, controlled coercivity and compensation point in multilayers, are associated with the interfacial magnetism. The temperature dependence of magnetic properties is controlled by the interfacial magnetism, which also is the key to obtain the desired properties for practical applications. 

Several results about the magnetization can be found from figs. 9a and 10. To understand the layer-thickness dependence of magnetization, both the antiferromagnetic coupling of Dy and Fe moments and the modulated distribution of composition have to be taken into account, (i) Sample 5 ADy/6.25 AFc is in a state close to the compensation point the Dy moment dominates for X <6.5 A and the Fe moment dominates for X > 6.5 A. (ii) As X increases from 2.5 to 6.5 A, the magnetization magnitude of Dy/Fe,... 

Figure 9b (Shen 1994) shows the Dy layer-thickness dependence of hysteresis loops of T A Dy/5 A Fe as the Dy layer thickness varies from 6.5 A to 5 A note especially (i) although the thickness interval is only 0.5 A, the coercivity and magnetization are very strongly dependent on thickness as the Dy layer thickness Y approaches 5 A where sample 5 A Dy/5 A Fe is in a state close to the compensation point, (ii) Compared with the loops in fig. 9a, the loops in fig. 9b illustrate much better squareness because these samples were coated with a 500 A SiO layer to protect fi om oxidation.

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