Hosts: Josef Fidler (TU-Wien), Thomas Schrefl (Donau-Uni Krems), Dieter Süss (TU-Wien)
Time: Friday, May 6th, 2016, 2:00 PM
Location: TU Wien (48°12'02.2"N 16°21'49.2"E)
Getreidemarkt 9, 1060 Vienna
Seminar room TUtheSky (11th floor)
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.
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