sputtering with a background pressure better than 2 107 Torr.
An Fe50Pt50 alloy target was used for film preparation. The samples
were deposited at room temperature (RT), and then immediately
transferred to a RTA chamber under vacuum for annealing. The
heating ratewas fixed at 40 C/s and the annealing temperature (Ta)
was varied from 450 to 800 C for 0 s. In-plane residual stress of
FePt films was examined by asymmetric sin2j method, which facilitates
residual stress measurement in thin film with strong
texture, based on x-ray diffractometry (XRD) technique [16]. The
grazing incidence angle of x-ray beam was fixed at 3. Synchrotron
radiation x-ray beam with energy of 8 keV was adopted for examination
of residual stress at beamline 17B at Taiwan Light Source
and beamline 12BM at SPring-8 in Japan. The details regarding to
stress measurement have been reported elsewhere [17]. Chemical
composition of the FePt films was analyzed by inductive coupled
plasma. Crystallographic structure and texture of the samples was
examined by XRD using a Cu Ka radiation. Magnetic properties of
the films were recorded at RT by a vibrating sample magnetometer
(VSM). Prior to VSM measurement, a pulse magnetic field of
~70 kOe was applied on samples to approach their magnetically
saturated states. Microstructure of the samples was observed by
transmission electron microscopy (TEM). Average grain size was
determined by measuring individual grain size in several dark-field
images. Surface chemical property was analyzed by x-ray photoelectron
spectroscopy (XPS) using synchrotron radiation at beamline
24A, Taiwan Light Source.