Detecting dynamic signals of ideally ordered nanohole patterned disk media fabricated using nanoimprint lithography

Abstract

The authors have fabricated ideally ordered alumina nanohole patterned disk media via anodic oxidation and nanoimprint lithography with a thermoplastic resist. The ordered arrays of alumina nanoholes with 100nm pitch, filled with Co by electrodeposition, were created over a macroscopically large area on a hard-disk substrate using these industrially applicable nanofabrication technologies. Stable flight of a perpendicular magnetic head above the media and perpendicular magnetic anisotropy of the Co nanopillars enable high-speed dynamic magnetic recording and playback. Dynamic periodic signals that matched the nanopillar periodicity were clearly observed after writing bit patterns, showing alternate reversal of magnetization of the nanopillars.

Recording media research for future hard disk drives

“…With this method, 40 nm dots could be fabricated [57]. Another method, proposed by Oshima et al, is to combine anodized alumina nano-hole with NIL [58]. In this method, the long-range ordering in alumina nano-holes were enhanced by lithographically produced tracks.…”

Highly organised and dense vertical silicon nanowire arrays grown in porous alumina template on <100> silicon wafers

“…Low-cost and versatile fabrication of functional nanostructures, for example for nanowires, nanocrystals or nanotubes, becomes of great importance in an increasing number of potential commercial devices [1-6]. In this context, the general approach of directed self-assembly (DSA) seems to be favoured by a high number of scientists and engineers because it uses natural properties and top-down methods to create nanostructures already positioned and organised.…”

“…These nanostructures offer a very large panel of applications including among others data storage with ferroelectric materials [1], sensors [2] and supercapacitors [3]. More specifically, porous AAO can be used to guide the growth of mono-crystalline nanowires by chemical vapour deposition (CVD).…”

Enhanced growth of anodic alumina nanochannels on Ga-ion pre-irradiated aluminum

“…[15][16][17][18][19][20] The size of such nanochannel arrays can be as large as 1 cm 2 , 21 and many potential applications are being realized recently. 22 The guiding nanohole arrays are fabricated by methods that change different physical or chemical properties of the Al. For example, when a Ga focused ion beam ͑FIB͒ is employed to fabricate the nanoholes by direct-ion writing, 16 geometric holes are created by physical sputtering while the chemistry of the Ga + -irradiated area is also changed due to accompanying ion implantation.…”