Session D40 - Poster Session I.
POSTER session, Monday afternoon, March 12
Exhibit Hall, Washington State Convention Center
The preparation and study of ultrathin films of metal-metal antiferromagnetics is important both for fundamental studies of surface-driven magnetic phenomena, and for the understanding of exchange bias. Ultrathin alloy films of Ni and Mn have been grown by depositing Mn on 4 ML Ni(111)/W(110), and annealing to 550 K. Directional Auger electron spectroscopy (DAES) shows that the films have short range structural order that is at most slightly distorted from fcc (111). LEED reveals that the films have long range order due to chemical ordering of the Ni and Mn. Depending on the Ni:Mn ratio, the experiments are consistent with structures similar to bulk Ni_3Mn, bulk NiMn, and a subsurface structure similar to the (\sqrt3 \times \sqrt3)R30, 2:1 surface alloy observed for Mn/Cu(111). The magnetic properties of these ultrathin film alloys are currently being investigated.