THE USE OF EXFOLIATED ZYH GRAPHITE FOR STUDIES OF HE-3 FILMS

Thin films of solid He-3 are excellent examples of two-dimensional mag netic systems. The first atomic layer is a paramagnet at coverages whe re the second solid layer exhibits either ferromagnetic or antiferroma gnetic behavior, depending on the coverage. Grafoil, an exfoliated pro duct of Union Carbide, is generally used as the substrate. However, th e atomically smooth crystalline platelets of Grafoil are typically 100 Angstrom in diameter, so a substrate with larger platelets would be u seful for magnetization studies where domain size is important. Exfoli ated ZYH graphite, with platelets in excess of 4000 Angstrom, is a goo d substitute for Grafoil. Adsorption isotherms and STM images for ZYH are discussed, and an experimental cell for magnetization measurements is described briefly.