The electron Fermi surface of HfB2

The de Haas‐van Alphen (dHvA) effect of HfB2 has been studied using a field modulation technique. Single crystal samples for the dHvA measurements were grown by a floating zone technique of rf heating. Observed dHvA oscillations in the (1010), (1120), and (0001) planes have frequencies of the order of 102 T. The values and angular dependence of the dHvA frequencies quite closely resemble those of an electron Fermi surface (FS) of ZrB2. It is proposed from an analogy with ZrB2 that HfB2 has a ring‐like electron FS around the K point in the Brillouin zone on which nearly ellipsoidal FSs are joined together and is a semi metal having carriers of 0.04 electrons (and holes) per unit cell though the oscillations corresponding to the hole FS could not be observed due to the sample limitation.