THERMOMAGNETIC ANALYSIS OF TH(2)FE(17)X(Y) COMPOUNDS (X=H, C, N)

A systematic analysis has been undertaken by means of thermomagnetic m easurements on the following compounds: Th2Fe17, Th2Fe17H5, Th2Fe17N3, Th2Fe17Cx, Th2Fe17CxH5-x. A cusp-like phenomenon is observed between room temperature and the Curie temperature in the temperature dependen ce of the magnetization, for all compounds studied. The origin of this anomaly is discussed and we suggest that it corresponds to a change o f the easy magnetization direction. A comparison is presented between this magnetic phase transition and that observed in some other interme tallic compounds as R(2)Fe(14)C or ThFe11Cx. We also discuss the modif ication of the transition temperature by the interstitial elements H, C or N.