Nanostructured magnetic recording media by patterning and glancing angle deposition

dc.contributorLi, Dawen
dc.contributorSong, Jinhui
dc.contributorWeaver, Mark Lovell
dc.contributorDean, Derrick R.
dc.contributor.advisorGupta, Subhadra
dc.contributor.authorSu, Hao
dc.contributor.otherUniversity of Alabama Tuscaloosa
dc.descriptionElectronic Thesis or Dissertationen_US
dc.description.abstractIn order to solve the trilemma problems that perpendicular magnetic recording is facing, advanced approaches such as heat assisted magnetic recording and bit patterned media are being intensively researched. In this work, high coercivity magnetic materials have been studied in the form of nanostructured Co/Pd and FeB/Pt multilayers. Arrays of uniformly spaced nanopillars over large areas were formed by utilizing block copolymer patterning. Uniform nanorods were formed by glancing angle deposition, a unique single-step approach to bit-patterned media. First, a detailed study on Co/Pd multilayered thin films was carried out to optimize the magnetic properties with respect to the thickness ratio, number of bilayers and seed layers. Then a statistical optimization of the patterning of Co/Pd multilayers by nanosphere lithography and block copolymer templating was carried out. The highest measured perpendicular anisotropy for Co/Pd films was 2.8 x 10<super>6</super> ergs/cm<super>3</super>. However, many of the M-H loops for Co/Pd were not saturated at the maximum field of 18 kOe, so the perpendicular anisotropy approaches 10<super>7</super> ergs/cm<super>3</super>. A unique single-step approach to nanostructuring these Co/Pd multilayers was developed: glancing angle deposition (GLAD), which produced Co/Pd nanorods with a coercivity as high as 2.9 kOe, a 123% increase over the flat multilayers. For deposition of FeBPt based granular media, two different techniques were used to sputter FeB/Pt multilayers. A finely alternated layered structure was proven to be more effective in forming L1<sub>0</sub> structured B-doped FePt. The FeBPt films thus formed were also patterned by block copolymer templating, and their magnetic properties were studied as a function of ion milling and annealing conditions. The highest coercivity achieved for patterned and annealed B-doped FePt films was 14 kOe.en_US
dc.format.extent140 p.
dc.publisherUniversity of Alabama Libraries
dc.relation.hasversionborn digital
dc.relation.ispartofThe University of Alabama Electronic Theses and Dissertations
dc.relation.ispartofThe University of Alabama Libraries Digital Collections
dc.rightsAll rights reserved by the author unless otherwise indicated.en_US
dc.subjectMaterials science
dc.titleNanostructured magnetic recording media by patterning and glancing angle depositionen_US
dc.typetext of Alabama. Department of Metallurgical and Materials Engineering Engineering University of Alabama
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