The Preparation Of Nanostructures And Research Of Perpendicular Exchange Bias

With the development of the information industry and the increased of the density ofmagnetic record media, the properties of the magnetic record media become very important.Due to the exchange bias effect is regarded as a valuable extension to complement in thedevelopment of the magnetic read heads, so the exchange bias effect has experienced arenaissance of research activity in recent years. However, most of them are fabricated on theflat substrate, and few researches are performed by depositing the film on the curved substrate.In this paper, the sample will be fabricated on the curved substrate of PS colloid sphere arraysusing magnetron sputtering system. This thesis includes following several parts: first, theorderd nanostructures are fabricated; second, the multilayer nanobowls are fabricated and themagnetic properties are studied; third; the perpendicular exchange bias are researched bychanging the size of nanosphere substrate and the thickness of CoO. And the results were asfollowing:Ⅰ. Magnetic behaviors of2D [Co/Pt]n multilayer nanobowl arraysThe magnetic nanobowls with perpendicular anisotropy were fabricated by depositingthe [Co/Pt]n multilayer on polystyrene (PS) bead array. By thinning the PS beads, thetopography of nanobowls were controlled. The coercivity of nanobowls showed dramaticenhancement compared to flat film.Ⅱ. The studies of perpendicular exchange bias of [Pt/Co]n/CoO multilayerPolystyrene nanosphere arrays are used as the substrate for [Pt/Co]nCoO multilayerdeposition. The effects of nanosphere size and CoO thicknesses on the magneticproperties of [Pt/Co]nCoO multilayer nanocaps are investigated. With decreasingnanosphere diameter, the nanocaps exhibit systematic variations of coercivity, exchangebias field and switching field distribution.III.The effects of stress in the curved magnetic multilayers[Pt/Co/CoO]nWe stusy the magnetic multilayers[Pt/Co/CoO]n systematically through change the size ofnanosphere and the thickness of CoO. The square ratio of the loop decreases first andincreases then with the reduction of tensile stress when the nanosphere size increases. In addition, the easy axis of [Pt/Co/CoO]n multilayer is tailored when the CoO sublayerthickness changes, which is due to the gradual development of a tilted anisotropy.