The effect of underlayer for Ba-ferrite sputtered films on c-axis orientation

A thin amorphous Ba-Fe-O film was deposited as an underlayer for the growth of c-axis oriented hexagonal barium ferrite (BaM) films using a facing targets sputtering system. This underlayer facilitates the crystallization and improves the crystallinity for hexagonal M phase. BaM films with c-axis orientation can be prepared at Ts of 525 degrees C on the underlayer. BaM films prepared on this amorphous underlayer exhibit a good c-axis orientation with c-axis dispersion angle Delta theta(50) as Small as 3 degrees. It is shown by the x-ray photoemission spectroscopy profile that this underlayer prevents deep diffusion of Ba and Fe into the substrate surface. (C) 1997 American Institute of Physics.