SURFACE STUDIES OF THE FERROMAGNETIC ALLOY PT3CR

The crystallographically ordered Pt3Cr (L1(2) structure) is a ferromag netic alloy. We have made the first direct measurements of its electro nic structure using ultraviolet photoelectron spectroscopy from the (1 10) surface. We find that the measurements are consistent with previou s calculations of the density of states (DOS). The DOS near the Fermi level is dominated by the chromium contribution. Studies of the (110) surface using Auger electron spectroscopy are consistent with stoichio metry. Low energy electron diffraction studies indicate that the surfa ce forms a (2 x 1) reconstruction with the repeat length in the [001] direction being twice that expected from a simple termination.