Search

A study of the effects of the thermal stability on the interface structure and magnetic as well as magnetoresistive properties is done for the Co/AlO interlayer CoFe/NiFe magnetic tunnel junction is presented. The reduction of the tunnel magnetoresistance ratio for the low annealing temperature (200 degree centigrade) is caused by the spin flip scattering at oxide ion, rather than by the change in magnetic properties.

Different optimal operating conditions for a C3-corrected transmission electron microscope were compared for both conventional field emission sources and for the next generation of monochromated instruments. In particular, the contrast transfer functions and corresponding wave aberration functions for two previously proposed optimal conditions in which C3 is adjusted to compensate, respectively, C5 or Cc are critically compared. The results indicate that in the presence of a small positive C5 the former provides flat transfer to the information limit whereas the latter shows oscillatory transfer at high spatial frequencies, which is more pronounced for the monochromated instrument. The effects of this behaviour were further investigated through multislice simulations of Si [110] and diamond [110] under the C5-limited condition. These confirm that for the former structure with an interatomic separation of 0.14 nm this aberration has little influence, but that for the latter with a sub-0.1 nm interatomic separation its presence leads to a restricted defocus range over which the structure is faithfully resolved. [ABSTRACT FROM AUTHOR]