In summary, we demonstrate the dependence of annealing
temperature on the evolution of microstructure, in-plane residual
stress, and crystallographic orientation of the rapid-annealed FePt
films. The stress-driven PMA and (001) texture of the L10 FePt films
were achieved at Ta 700 C. By microstructural observation and
in-plan stress measurement, we provide an unambiguous evidence
for the tensile stress which partly originates from the annihilation
of grain boundaries of L10 FePt grains. The progress of L10 ordering
causes the relaxation of the in-plane tensile stress of the FePt. On
the other hand, the surface oxidation of the L10 FePt was proposed,
for the first time, to be the unexpected second source of the tensile
stress during RTA. This fundamental study provides useful knowledge
for understanding the stress behavior of FePt during RTA by
characterizing the microstructure and crystallographic structure