The crystal structure, magnetic susceptibility, electrical resistivity, specific heat, and electronic band structure of RAuGe (R=Sc,Y,La,Lu).

Schnelle W., Pöttgen R., Kremer R.K., Gmelin E., Jepsen O.

Max-Planck-Institut für Festkörperforschung, Heisenbergstraße 1, D-70569 Stuttgart, Germany

The title compounds were prepared by arc melting of the elements and subsequent annealing. Their structures were refined from single-crystal X-ray diffractometer data. While YAuCe and LaAuGe adopt the structure of NdPtSb, the structures of ScAuGe and LuAuGe are more closely related to that of LiGaGe. The crystal chemistry of these germanides is briefly discussed. The four compounds are weak diamagnets. The ratios of their Pauli susceptibilities and their electronic specific heat coefficients are the same for the Y, La, and Lu compounds. The electrical resistivities of ScAuGe and LuAuGe are metal-like (60/90 mu Omega cm), while YAuGe and especially LaAuGe show much higher resistivities which saturate at high temperatures (800 mu Omega cm for LaAuGe at 300 K). The electronic properties of the four compounds are discussed on the basis of TB-LMTO-ASA band-structure calculations. Differences in the phononic specific heat of the compounds result both from the different molar masses and the strong elongation of the lattice parameter c with the R-atom radii.

A full reprint of this paper is available as postscript or PDF file from the IOP WWW-Server.

Journal of Physics: Condensed Matter, 9 1435-50, 1997.

Max-Planck Institut für Festkörperforschung;
Postfach 80 06 65   D-70506 Stuttgart