DE-HAAS-VAN-ALPHEN EFFECT AND ENERGY-BAND STRUCTURE IN UB2

We grew a single crystal of UB2 with the hexagonal structure and obser ved the de Haas-van Alphen (dHvA) oscillation. All of the dHvA branche s, which are about seven in number. are detected in the limited angle regions. They are well explained by the 5f-itinerant relativistic band theory with an exchange and correlation potential in a local density approximation. Namely, UB2 is a compensated metal with an equal number of electron and hole. The Fermi surface consists of two closed hut co rrugated Fermi surfaces. The cyclotron masses are moderately heavy, ra nging from 1.2 to 7.7m(0).