An investigation of the chemistry of the dielectric/FeCoTb interface by x‐ray photoelectron spectroscopy and Auger electron spectroscopy

The interfacial chemistry of magneto‐optic structures of sputter deposited SiO, SiO2, Si3N4/FeCoTb/SiO, SiO2, and Si3N4 was studied in detail by x‐ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES). XPS and AES depth profiles have revealed a substantial amount of redox chemistry at the dielectric/rare‐earth transition metal interfaces. The chemical reactions occur preferentially with the terbium as revealed in the XPS portion of the study by the formation of terbium oxide and terbium silicide. In the case of Si3N4 evidence of TbNx has also been observed. ‘‘As deposited’’ and annealed samples of the magneto‐optic structures are compared and contrasted. It is concluded that Si3N4 is a superior dielectric for magneto‐optic media.