SCANNING-TUNNELING-MICROSCOPY STUDIES OF PT80FE20(110)

Results of scanning tunnelling microscopy (STM) show that two differen t kinds of surface structures coexist on the (110) sur-face of Pt80Fe2 0. The predominant structure corresponds well to the missing row type (1 x 2) reconstruction previously observed on, for example Pt(110), wh ereas the minority domains show a faintly buckled structure with appro ximately (1 x 1) geometry. Based on the STM images, we propose that th e two domains have different surface chemical compositions and corresp ond to two different metallurgical phases known for the PtFe system at this composition.