The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-d...The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-deposits a Ag underlayer on the MgO substrate.For films with higher roughness,a marked rise in coercivity is observed.Three factors are discussed to be mainly responsible for the coercivity rise,involving the formation of pinholes,the reduction of exchange coupling between Fe and Ni layers,and Fe-Ni alloying at interfaces.展开更多
The dynamic performance of heat assisted magnetic recording （HAMR） on different media is investigated. Signal and signal-to-noise ratio enhancement are achieved in high coereivity perpendicular media with the aid of...The dynamic performance of heat assisted magnetic recording （HAMR） on different media is investigated. Signal and signal-to-noise ratio enhancement are achieved in high coereivity perpendicular media with the aid of laser heating. Linear recording density is increased while saturation write current is lowered. Trailing field partial erasure is observed in lower coercivity media with a ring head, which causes signal reduction with increasing write current or application of a laser. Precautions should be taken against partial erasure in overall recording system optimization of HAMR in order to achieve ultrahigh recording density.展开更多
The influence of the electropolishing and anodization voltage on surface morphology has been carefully studied for fabrication of ordered anodic aluminum oxide （AAO） templates. In accordance with that in the anodiza...The influence of the electropolishing and anodization voltage on surface morphology has been carefully studied for fabrication of ordered anodic aluminum oxide （AAO） templates. In accordance with that in the anodization experiment, the size of small patterns on the foil surface formed from the electropolishing treatment increases with voltage. Using a combined method of small-voltage eleetropolishing and anodization, we have fabricated well ordered templates with much smaller interpore distances compared with that under normal-voltage fabrication conditions. The Ni nanowire arrays with two small diameters are eleetrodeposited through the above templates, exhibiting different magnetic properties. This also helps us to clarify the inner structure of this kind of templates.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos 51071046,61078030,11074046,11174056,11274113the National Basic Research Program of China(2009CB929201)the Characterization Facility,University of Minnesota,a member of the NSF-funded Materials Research Facilities Network(www.mrfn.org)via the NSF MRSEC program under award number DMR-0819885.
文摘The influence of surface/interface roughness on the magnetic properties of Fe/Ni multilayers is investigated.Two methods are employed to tune the film roughness:one varies the substrate temperature,and the other pre-deposits a Ag underlayer on the MgO substrate.For films with higher roughness,a marked rise in coercivity is observed.Three factors are discussed to be mainly responsible for the coercivity rise,involving the formation of pinholes,the reduction of exchange coupling between Fe and Ni layers,and Fe-Ni alloying at interfaces.
基金Supported by the National Natural Science Foundation of China under Grant Nos 60490290, 60678008, 10604016, 50771032, a.nd 5C1771{}33. the National Basic Research Program of China under Grant No 2009CB929201.
文摘The dynamic performance of heat assisted magnetic recording （HAMR） on different media is investigated. Signal and signal-to-noise ratio enhancement are achieved in high coereivity perpendicular media with the aid of laser heating. Linear recording density is increased while saturation write current is lowered. Trailing field partial erasure is observed in lower coercivity media with a ring head, which causes signal reduction with increasing write current or application of a laser. Precautions should be taken against partial erasure in overall recording system optimization of HAMR in order to achieve ultrahigh recording density.
基金Supported by the National Natural Science Foundation of China under Grant Nos 50771032, 50771033, 10604016 and 60678008, and the National Basic Research Program of China under Grant No 2009CB929201.
文摘The influence of the electropolishing and anodization voltage on surface morphology has been carefully studied for fabrication of ordered anodic aluminum oxide （AAO） templates. In accordance with that in the anodization experiment, the size of small patterns on the foil surface formed from the electropolishing treatment increases with voltage. Using a combined method of small-voltage eleetropolishing and anodization, we have fabricated well ordered templates with much smaller interpore distances compared with that under normal-voltage fabrication conditions. The Ni nanowire arrays with two small diameters are eleetrodeposited through the above templates, exhibiting different magnetic properties. This also helps us to clarify the inner structure of this kind of templates.
