IEEE Magnetics Society
Santa
Clara Valley Chapter
Monday, March 7th, 2016
Western Digital, 1710
Automation Parkway, San Jose, CA 95131
Directions
and Map
Cookies, Conversation
& Pizza at 6:30 P.M.
Presentation at 7:00 P.M.
Materials challenges for next generation high-density magnetic recording - media and readers
Prof. Kazuhiro Hono, National Institute for Materials Science (NIMS), Tsukuba, Japan
Abstract
The hard disk drive industry is making continuous efforts to increase the
areal density of magnetic recording. To realize an areal density of higher than 2 Tbit/in2 in the future,
both media and readers need technical breakthroughs. Since the bit size will be in the range of 20 nm,
the magnetic grains in the recording media must be reduced to less than 6 nm, requiring the use of ferromagnetic
materials with high magnetocrystalline anisotropy such as L10 FePt. The shield-to-shield spacing of read sensors
must also be smaller than 20 nm with low device resistance (resistance-area product RA~0.1 m2), which is very
difficult to achieve using MgO based tunneling magnetoresistance devices. In this talk, we will address the materials
challenges to the realization of an ideal media nanostructure using L10 FePt for heat-assisted magnetic recording (HAMR)
media and narrow readers for > 2 Tbit/in2 areal density. Recently significant progress has been made in current-perpendicular-to-plane
giant magnetoresistive (CPP-GMR) devices using highly spin-polarized Heusler alloy ferromagnetic layers and new spacer materials.
The very high magnetoresistance ratios achieved in CPP-GMR are encouraging for future read head applications of CPP-GMR, or its
laterally extended version, lateral spin valves. The devices with high magnetoresistive output at low RA may open new applications
in addition to disk read heads.
Biography
Kazuhiro Hono received the BS and MS degrees in Materials Science from Tohoku
University in 1982 and 1984, respectively, and a Ph.D. degree in Metals Science and Engineering from Penn
State in 1988. After working as a post doc at Carnegie Mellon, he became a research associate at the Institute
for Materials Research, Tohoku University in 1990. He moved to the National Research Institute for Metals
(currently National Institute for Materials Science, NIMS) as a senior researcher in 1995, and is now a NIMS
Fellow and the Director of the Magnetic Materials Unit. He is also a professor in Materials Science and Engineering
at the Graduate School of Pure and Applied Sciences, University of Tsukuba. His current research interest is
materials science in magnetic and spintronics materials and their devices. He is also active in the development
of high performance permanent magnets without critical elements.
Link to presentation material.
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