Ordered alloy films of Ni and Mn grown on Ni(111)/W(110)

Ultrathin films of alloyed Ni and Mn have been grown by depositing Mn on 4 ML Ni/W(110) and annealing to 550 K. Directional Auger electron spectroscop y (DAES) shows that the films have short-range structural order that is at most slightly distorted from the f.c.c. (111) structure of the Ni film. Low energy electron diffraction (LEED) shows that the films have long-range or der due to chemical ordering of the Ni and Mn. Depending on the Ni:Mn ratio , the LEED and DAES are consistent with structures similar to bulk Ni3Mn, b ulk NiMn, and with a subsurface structure similar to the (root3 X root3)R30 2:1 surface alloy observed for Mn/Cu(111). (C) 2001 Elsevier Science B.V. All rights reserved.