Paper AS-ThP4
Surface Modification of Multiferroic BiFeO₃ Ceramic by Argon Sputtering

Thursday, October 31, 2013, 6:00 pm, Room Hall B

Films fabricated by sputtering deposition are extensively used in semiconductor, optical and optoelectronic industries. Since the sputtering is the key to physically deposit the films onto substrates, its effect on the target materials is needed to investigate in order to fabricate films successfully. In this study, multiferroic bismuth ferrite, BiFeO , (BFO) with 5 mole% BaTiO₃ target was sputtered by using 3 keV argon ions continuously after various time intervals. The X-ray Photoelectron Spectroscopy (XPS) was applied to examine the cleanness and the chemical environment of the elements on the sample surface after each sputter time interval. The carbon contaminant was almost completely removed after 5120 s sputtering, but the sputtering induced metallization of the bismuth and two-component oxygen spectra were also observed. It was found that the oxidation states of bismuth from dominant 3+ state changed to equally weighted 3+ state and 0 state. The changes of the valence electrons of bismuth induced by the argon sputtering on the BFO target inevitably alter the film compositions deposited onto the substrate; however, it was found that the non-stoichiometric BFO films can be corrected by sputtering under partial oxygen pressure via the re-oxidation of bismuth metal.