Interlayer Exchange Couppling In Pt/Co Mutilayers With Magnetic Anistropy

Since the discovery of an antiferromagnetic interlayer coupling in Fe/Cr multilayers with in-plane anisotropy,interlayer coupling has attracted considerable attention due to application in high-density date storage.The control of the magnetical interlayer couppling and magnetism tropism in magnetical multilayers is the key of the realization of magnetic resistivity device under the great magnetic resisitivity(GMR)effective and tunneling magnetic resisitivity(TMR) effective. The interlayer exchange couplling in Pt/Co multilayers is investigated in the paper.The antiferromagnetic interlayer exchange couppling in the Pt/Co multilayers with perpendicular anistropy is discovered.The experiment result indicates that the temperature shows vital importance on the interlayer exchange couppling sign.The results in the paper has a great significance for the Pt/Co multilayers application in high-density date storage.Firstly,two methods of low angle X ray diffraction and quality weighing are used to determine the magnetron sputtering film's deposition rate and the data processing method of the original extraordinary hall effect loop and magneticresistivity effect loop is analysed in the second chapter. Secondly,through the extraordinary hall effect loop mersurement of the multilayer [Pt (27.5 ?) /Co (tCo ?)]n/NiO (10.5 ?),it is found that magnetic anisotropy transit from in-plain anisotropy to out of plain anisotropy as the Co layer thickness increase from 3 ? to 7 ?.The interlayer exchange coupling shows ferromagnetic interlayer coupling while the multilayers repeating number is two.As the repeating number increases,the antiferromagnetic interlayer coupling is observed.Thirdly,through the calculation of the relationship between the interlayer exchange coupling sign and temperature of the multilayer [Pt (27.5 ?) /Co (4 ?)]3/NiO (10.5 ?),we can know that the interlayer exchange coupling transit from ferromagnetic interlayer coupling to antiferromagnetic interlayer coupling when the temperature raise to 369K.Finally,the influence of the Pt layer thickness and NiO layer thickness on the magnetic property in the multilayers [Pt(tPt ?)/Co(4 ?)]3/NiO(tNiO ?)/[Co (4 ?) /Pt (tPt ?)]3 is studyed at the last chapter.Through the messurement of extraordinary hall effect loop of the [Pt(29.5 ?)/Co(4 ?)]3/NiO(11?)/[Co (4 ?) /Pt (29.5?)]3 multilayer at different temperature ,we can conclude that the thermal effect in the magnetization of the Co layers can lead to the ferromagnetic-antiferromagnetic transition of the interlayer coupling at high temperature due to its strong effect on the phase of electron reflectivity at the Pt/Co interfaces.