Superconducting properties of BeB2.75

D. P. Young, Louisiana State University
R. G. Goodrich, Louisiana State University
P. W. Adams, Louisiana State University
Julia Y. Chan, Louisiana State University
Frank R. Fronczek, Louisiana State University
F. Drymiotis, National High Magnetic Field Laboratory
L. L. Henry, Southern University and A&M College


We present the low-temperature electronic transport properties of the intermetallic commonly known as BeB2. In contrast to the much simpler A1B2-type structure of the 39-K superconductor MgB2, BeB2 forms a complex structure-type that is nearly unique in nature. The structure has 110.5 atoms per unit cell and a stoichiometry BeB2.75. Polycrystalline Be(10.8B)2.75 is superconducting below Tc=0.72 K with a critical magnetic field Hc2=0.175 T. Isotopically pure 10.0B samples have an enhanced Tc=0.79 K. Hall-effect measurements suggest that the material is intrinsically compensated.