  Off-axis electron holography was used to observe and quantify the magnetic
microstructure of a perpendicular magnetic anisotropic (PMA) recording media.
Thin foils of PMA materials exhibit an interesting up and down domain
configuration. These domains are found to be very stable and were observed at
the same time with their stray field, closing magnetic flux in the vacuum. The
magnetic moment can thus be determined locally in a volume as small as few tens
of cubic nanometers.
