Magnetic properties of the pseudo-binary GdGa2-xAlx compounds

The effect of substitution of Al for Ga on the lattice parameters and the magnetic properties of the GdGa2-xAlx compounds has been studied. It was found that there is an abrupt change in the lattice parameters at the ill concentration range x = 0.6-3.75. With increasing Al concentration, the lattice parameter a increases whereas c decreases. From the magnetic measurements, it is likely that the compounds with low Al concentration (0 less than or equal to x less than or equal to 0.3) have a complex magnetic structure, whereas for higher Al concentration (0.5 less than or equal to x less than or equal to 1.2) the compounds can be described well as simple antiferromagnets. The change of the magnetic properties of GdGa2-xAlx is attributed to the change in distance between the Gd atoms and to the conduction electron concentration with increasing Al concentration. (C) 1999 Elsevier Science B.V. All rights reserved.