OBSERVATION OF FE-MN OXIDATION PROCESS USING SPECIMEN TRANSFER CHAMBER AND ULTRAHIGH-VACUUM TRANSMISSION ELECTRON-MICROSCOPE

A specimen transfer chamber that enables a specimen to be transferred in vacuum from a thin-film growth apparatus to an ultrahigh-vacuum transmission electron microscope (UHV-TEM) was developed. This chamber was applied to observe, for the first time, the as-grown state-of Fe-Mn thin films and the changes occurring during their oxidation. The oxidation process of 12-nm-thick Fe-Mn films on a carbon support film was observed by controlling the vacuum in the transfer chamber. Just after a film specimen was transferred, it had a polycrystalline single-phase structure. When the film was exposed to pressures from 3.8 X 10(-6) Pa to 1 atm, (Fe-Mn)203 gradually appeared around the Fe-Mn grain boundaries. The Fe-Mn grains changed to (Fe-Mn)2O3 grains after 47 h of exposure to air.