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S e p t e m b e r 2 4 - 2 6 , 2 0 1 8 | B u d a p e s t , H u n g a r y
Magnetic Materials 2018
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Page 27
MAGNETISM AND
MAGNETIC MATERIALS
2nd International Conference on
Materials Science and Nanotechnology | Volume 2
OF EXCELLENCE
IN INTERNATIONAL
MEETINGS
YEARS
Sandeep Kumar Srivastava, Mater Sci Nanotechnol 2018, Volume 2
BIT PATTERNED MEDIA- PROBING
MAGNETIC PROPERTY USING EHE
MEASUREMENT
T here is a frantic race to increase the storage density of hard disk drive
(HDD) due to its huge applications. The recording media used for making
conventional HDD is made up of multilayers thin film or magnetic alloys, which
naturally forms nanometer-scale grains and each recorded bit is stored across
hundreds of these magnetic grains. Although, the conventional perpendicular
media is being used in current recording technology, but it is expected to lose
its fuel in next few years due to a phenomenon called super-paramagnetism
(thermal stability of recorded bit). Recently, one alternative potential way has
been proposed, so called bit patterned media (BPM). In such bit patterned
media, each artificially fabricated magnetic nanostructure can store an
individual bit rather than using hundreds of naturally formed small grains to
store single bit. Ordered arrays of isolated magnetic nanostructures are of
considerable interest to increase the storage density of hard disks beyond the
current perpendicularmedia. In such bit patternedmedia (BPM), each artificially
fabricated magnetic nanostructure can store an individual bit. We developed a
novel non-lithographic method to fabricate perpendicularly magnetized BPM
system and we studied Co/Pt bit pattern media. In present talk, the author will
discuss few results onCo/Pt bit patternmedia, aswell as results onCoTb alloys-
based bit patterned media. These materials were fabricated using the barrier
layer of auto-assembled anodic alumina template (a non-lithographic method)
and by depositing either CoPt multilayers or CoTb alloy to form an ordered
array of ferromagnetic nanodots, so-called nanobumps. We used extraordinary
hall resistance measurements to probe magnetization reversal mechanism
and switching field distribution. The role of interdot exchange coupling and
dipolar coupling, magnetization reversal process will be discussed.
Biography
S K Srivastava is working as an Associate Professor
and Head at Department of Physics, CIT Kokrajhar
India. Moreover, he is serving the institute as Dean
(R&D). He is recipient of Early Carrier Research
Award 2017; given by Ministry of Science and Tech-
nology (DST-SERB), Government of India. He is prin-
ciple investigator of two projects. He has a strong
interest to work in material science with a special
emphasis to magnetic materials for wide range of
applications. He has publishedmore than 50 papers
and has delivered several invited talks in India and
abroad.
Sandeep Kumar Srivastava
Central Institute of Technology, India