T. Strassle et al., Crystal-field interactions in the pseudo-ternary compound ErAlxGa2-x studied by inelastic neutron scattering, J PHYS-COND, 13(31), 2001, pp. 6773-6785
The crystal field of the pseudo-ternary compound ErAlxGa2-x has been determ
ined by means of inelastic neutron scattering for x = 0.5, 1.0 and 1.75. Th
e thermodynamic properties reconstructed from the obtained crystal-field pa
rameters are compared to neutron diffraction, specific heat and magnetic su
sceptibility measurements. The effect of increasing the Ga concentration on
the crystal-field potential with respect to the change in geometry and the
electronic properties of the solid is discussed by means of an extended po
int-charge model. It is concluded that Ga leads to an increase of the elect
ron concentration and thus most likely triggers the structural phase transi
tions in the RAlxGa2-x systems (R = rare earth) by a Hume-Rothery-like elec
tronic mechanism. The experimentally observed large broadening of the cryst
al-field transitions is discussed within the framework of concentration inh
omogeneities.