Fermi Surface of Osmium

The Fermi surface for osmium is found to bear a close relationship to that for ruthenium, with corresponding areas comparable or smaller. The de Haas-van Alphen frequencies observed fall into two distinct ranges differing by a factor of about 50, the higher centered at 1.5 × ${10}^8$ G. The energy bands calculated for rhenium with a Fermi energy appropriate for osmium suggest a Fermi surface consisting of three large sheets — a pair of nested electron-type surfaces and an open hexagonal network of hole-type arms. Our measurements clearly detect each of these surfaces. We observe additionally a single set of small ellipsoids. If these ellipsoids are hole surfaces located on faces of the Brillouin zone near $U$, only minor modifications of the bands calculated for rhenium are required to bring the Fermi surface into agreement with the experimental results.