ENHANCEMENTS AND FERMI SURFACES OF RARE-EARTH HEXABORIDES

The properties of rare-earth hexaborides have been studied within the framework of density functional theory. The LMTO-ASA method has been used to study the electronic structure of paramagnetic LaB6, CeB6, PrB6 and NdB6 and of ferromagnetic CeB6, PrB6 and NdB6. In the ferromagnetic case, which treats the f electrons as true band states, the authors find good quantitative agreement between the experimental and theoretical Fermi surfaces. In addition, comparison of spin moments and total energies is used to predict the zero-field susceptibility within a Landau free energy argument. This indicates that the experimentally heavy fermion system CeB6 does indeed have a substantially enhanced effective electron mass.