The crystal structure of CeCu2Ge2 under pressure

We have investigated the effect of hydrostatic pressure p on the crystal structure of CeCu2Ge2 up to p = 15 GPa. The lattice parameters and the unit cell volume decrease continuously, whereas the c/a-ratio increases. A bulk module of B0 = 98 GPa was fittet on the V(p) data. At p = 6.5 GPa, roughly the pressure where the AF-state is replaced by the SC-state, the volume of CeCu2Ge2 is equal to that of CeCu2Si2. A comparison of the structural parameters of CeCu2Ge2 under pressure with those of CeCu2Si2 at p = 0 indicates, that the 4f-hybridisation strength is determined by the Ce-Cu hybridisation. Further, non-hydrostatic pressure has a strong influence on the behaviour of the structural parameters. (orig.)