Surface premelting in Al(110) observed by core-level photoemission

Surface premelting has been observed on Al(110) by recording Al 2p core-level photoemission at temperatures from T=80 K up to 1 K below the Al bulk melting point (TM=933.5 K). By comparing spectra from Al(110) and Al(111) surfaces and from liquid aluminum the growth of a quasiliquid layer is established. The thickness of the layer is found to grow logarithmically with temperature, commencing at 150 K below the melting point, with a thickness of about 8 ML at 1 K below TM. The degree of local structure and density of the quasiliquid layer are determined to be identical to those of liquid aluminum.