Date: Wednesday, October 5, 2011
Time: 16:00 - 17:30
Place: 8th floor medium seminar room
We have studied highly L10-ordered FePtAg-C nano-granular thin films as
potential TAR media. These films were fabricated in a flexible sputter
system allowing deposition of appropriate adhesion, heat sink and seed
layers before growing FePtAg-C at elevated temperature to optimize grain
size, distribution, texture and chemical L10 ordering. We obtained granular
FePtAg-C films with well isolated grains, .e.g. of 7.4 nm +/- 1.4 nm, that
show high coercivities Hc up to ~5 T and are suitable for TAR recording
on glass substrates. Structural analysis suggests that the variation in
anisotropy field is the largest contribution to the observed switching
field distribution. In addition to optimized microstructure and magnetics,
TAR media should include a suitable thermal design, underlining the need
for thermal properties characterization. We will introduce our pump-probe
technique as a sensitive metrology tool for thin films and multilayers.
Anisotropy in the thermal conductivity due to grain microstructure in metallic
films and size effects in nanoscale materials will be discussed.