CHEMICAL VAPOR DEPOSITION OF THIN FILM MATERIALS FOR ...

pattern. Fig.44(b) has diffraction spots from both the film and the MgAl2O4 substrate. For lattice
planes with small miller indices the spots from the film and the substrate overlap with each other,
while for those with larger indices the separation of two spots can be observed.
Fig. 44. Electron diffraction pattern of nickel ferrite film grown on MgAl2O4 substrate at 600˚C. (a) diffraction
pattern from the nickel ferrite film only; (b) diffraction pattern from both the film and the substrate. Zone axis of
was selected for both diffraction patterns. Courtesy of Dr. R Datta for taking the electron diffraction data.
Diffraction contrast TEM images of the sample mentioned above under two beam
conditions have been obtained and are showed in Fig.45. The sample was tilted to make (-1-10)
the strongest diffraction spot. In this bright field TEM image, certain threading dislocations can
be clearly observed. These defects are probably from the strain relaxation process with thin film
growth. As we have found in the XRD measurement that the nickel ferrite films are fully relaxed
under these experimental conditions. HRTEM image of the interface between nickel ferrite and
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