MAGNETIC AND CRYSTALLOGRAPHIC PROPERTIES OF CE2CO17-XGAX COMPOUNDS

The structural and magnetic properties of Ce2Co17-xGax compounds for G a concentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements. The easy magnetisation direction is paralle l to the c axis in all compounds. The Co moments and the Curie tempera tures decrease strongly with increasing Ga concentration. From magneti c measurements made on magnetically aligned powders we have determined the concentration dependence of the anisotropy constant. The values o f K-1 increase up to x=3 and then strongly decrease with increasing x. This behaviour is discussed in terms of preferential Ga substitution into the available crystallographic sites, confirming earlier conclusi on that Co atoms at the 18h sites contribute negatively to the Co subl attice anisotropy in R2Co17-xGax compounds. (C) 1998 Elsevier Science S.A. All rights reserved.