Abstract： We calculate the critical temperature Tc of a wide range of diborides which have the same crystal structure as MgB2. Their electronic structure is also calculated in the framework of the local density approximation method of density functional theory by using the psudopotential plane wave approach. The Hopfield factors η of these materials are calculated by the frozen phonon method. Our results show that most of these diborides have low η, and hence low or no Tc, which are consistent with experimental observations. The most important result of our calculation is that AgB2 and AuB2 have higher Tc than MgB2. The high Tc of these two material comes from the combination of high density of states and high deformation potential of the σ bands.
YANG Fan;HAN Ru-Shan;TONG Ning-Hua;GUO Wei. Electronic Structural Properties and Superconductivity of Diborides in the MgB2 Structure[J]. 中国物理快报, 2002, 19(9): 1336-1339.
YANG Fan, HAN Ru-Shan, TONG Ning-Hua, GUO Wei. Electronic Structural Properties and Superconductivity of Diborides in the MgB2 Structure. Chin. Phys. Lett., 2002, 19(9): 1336-1339.
2002, Vol. 19 
