Magnetic and Semiconductor Nanostructures
for Ultra High Density Magnetic Recording

Ernesto E. Marinero
Hitachi San Jose Research Center

Magnetic recording aims to achieve recording densities of ≥ 1012 bits/in2 in the foreseeable future. Critical dimensions of the magnetic domains and the sensors required to detect their flux at this density will be of the order of 15 nm or less. These nanoscale dimensions present major materials and fabrication challenges to both the magnetic materials utilized for storing the bits, and to the sensor devices. This talk will review ongoing efforts to achieve highly uniform nanostructured magnetic recording materials comprising magnetic grains (islands) of   ≤ 5 nm in diameter, segregated by a secondary non-magnetic phase.

Mesoscopic sensors based on GMR and TMR based ferromagnetic materials are expected to be
inadequate for sensing magnetic domains ≤ 15 nm on account of thermal instabilities
(mag noise) and spin-torque effects. Therefore, magnetic sensor devices employing
non-ferromagnetic materials are needed. Nanoscopic semiconductor quantum well heterostructures
offer a potential solution and I will describe our ongoing research on Lorentz Magnetoresistive
Devices employing AlSb/InAs/AlSb transport channels.

Prof Marinero will be visiting Imperial College on Tuesday 13th May and would be interested to
explore the possibility of setting up international collaborations in the area of
nanotechnology. Please contact Lesley Cohen (l.cohenimperial.ac.uk) if you would like to
arrange a time to talk to Prof Marinero.