Studies Of Magnetic Properties On Patterned Magnetic Thin And Ultrathin Films

With the development of modern society, the demand of information by the human is greatly increased. A large amount of information requires a high-capacity storage media. Since the 1990s, the technoloies of various storage media have been grew rapidly, and magnetic thin film has also obtained considerable development. Spintronics has became a meaningful study for its irreplaceable position for fundamental mechanism of magnetie media. In order to learn the ultrafast process like magnetization reversal or precession of magnetie storage media, the use of traditional methods has been limited. Now, time resolved optical pump-probe technique has been used to study ultrafast spin dynamics.Micro/nano patterned array is the basic structure of magneto-electronic devices. Recently,With the development of patterned array of fabrication technology and progress of the thin film material fabrication technology, it is possible to study the magnetic behavior of small graphics array. For example, electron beam lithography(EBL), focused ion beam etching (FIB), interference lithography and nano ball method have been used to fabricatevarious magnetic unit. In recent years, it was found that the shape and structure of the graphic array have important influence on the magnetic properties of the unit. So how to control the shape anisotropy of the patterned magnetic thin film array is a very attractive research issue.First, this dissertation introduces the basic principle of focus magneto optical Kerr effect (Focus Moke) and time-resolved ultrafast magneto-optical Kerr effect (TRMOKE). Then the design and construction of t the Kerr effect measurement system (Focus Moke) and time-resolved ultrafast magneto- opticcal Kerr effect (TRMOKE) measurement system are introduced. Finally, by utilizing the focused magneto optic Kerr effect measurement system (Focus Moke), and the effect of the rectangular ratio of the patterned films on the anisotropy of the films was studied. The time-resolved ultrafast magneto-opticcal Kerr effect (TRMOKE) measurement system, through changing the power of the pump, was used to analyze the characteristics of the magnetic damping factor.