Magnetic Properties And Microstructure Of Sandwiched Transition Metal Nanofilms Deposited By Facing-Target Magnetron Sputtering

As packing density of magnetic recording enhancement,magnetic films compose of ferromagnetic metal particles,such as Fe,Co,Ni and their alloys,draw our attention on them,and become a major issue.In this experiment,We prepared Ag/Fe/Ag and Ti/Fe/Ti, and charactered the samples by the instrument,such as VSM,XRD and SPM.the findings are these:1.We prepared Ag(x nm)/Fe(15 nm)/Ag(x nm)(here x=1,2,3,4,5),and found that the coercivity of the samples have a great impact on Ag layer thickness.The values first increase then decrease as the Ag layer thickness increase.When the Ag layer thickness is 3 nm,the perpendicular membrane coercivity gets the maximum,the surface average roughness reaches the minimum,about 0.2 nm.We thought that the change of coercivity is considered as the contribution of shape anisotropy.2.We prepared Ti(x nm)/Fe(15 nm)/Ti(x nm)(here x=1,2,3,4,5),and found that the coercivity of the samples have a great impact on the Ti layer thickness.The values increase as the Ti layer thickness increase.When the Ti layer thickness is 3 nm and 5 nm, the perpendicular membrane coercivity was the maximum about 1710 Oe and 1864 Oe,we concluded that the origin of large coercivity is attributed to the the introduction of Ti.On the one hand,it leads to the improvement in the crystalline quality.On the other hand,the small scale Ti layer shows discontinuous island distribution on the substrate,like template, so it leads to Fe middle layer tend to grow in a columnar growth mode,and enhance shape anisotropy.Compared to Ag layer,it has been found that Ti layer is much better than Ag layer in the improvement of magnetic properties.3.We prepared Ag/Fe/Ag and Ti/Fe/Ti films.VSM result shows that the in-plane coercivity is larger than the out-of-plane coercivity after 500℃annealing.We concluded that the change is attributed to the reduction of intergrain interaction,which results from more nonmagnetic Ag atoms than Ti atoms into the grain boundaries of magnetic grains. 4.We studyed the time efficiency of Ag(3 nm)/Fe(x nm)/Ag(3 nm) films.We found that the magnetic properties of the samples have not been destroyed after two years.In contrast,the magnetic properties were slightly improved,the out-of-plane coercivity of all the samples slightly increase.We concluded that the change is attributed to the reduction of intergrain interaction,which results from the nonmagnetic Ag atoms into the grain boundaries of magnetic grains during placement.Compared to the result of Ti introduction, we found that the time-effect of Ag is much better than Ti.