Magnetic properties of Ce/sub 2/Fe/sub 17-x/Al/sub x/(N/sub y/) compounds

摘要

We have studied the magnetic properties of the rhombohedral Ce/sub 2/Fe/sub 17-x/Al/sub x/(N/sub y/) compounds. Aluminum substitution in Ce/sub 2/Fe/sub 17/ leads to ferromagnetism for medium Al concentration and to cluster glasses for high Al concentration. The Curie temperature shows a maximum. Rare-earth nitrides of the composition Ce/sub 2/Fe/sub 17-x/Al/sub x/N/sub y/ can be prepared by the reaction of Ce/sub 2/Fe/sub 17-x/Al/sub x/N/sub y/ with nitrogen gas at 500/spl deg/C. The crystal structure and lattice constants have been determined for all compounds. The Curie temperature enhances upon nitrogenation. The nitrogen absorption capacity decreases with composition x and vanishes for x<5. The enhancement of the Curie temperature of the nitrides decreases according to the absorption capacity.