On the new (R = rare earth metals) alloys and their related hydrides and carbides

New interstitial hydrides RFe11.35Nb0.65Hy and carbides RFe11.35Nb0.65Cy (R = rare earth metal) have been synthesized. Structural characteristics and preliminary magnetic properties (T-C and m(Fe)), together with those of the starting alloys, are presented and compared to the previously studied nitrides. Large increases of the Curie temperature and of the iron moment, particularly large in the carbides, are obtained. The evolutions of the deduced Fe-Fe and R-Fe exchange interactions are discussed. The large Curie temperature obtained with the carbides makes this series particularly attractive for permanent magnet applications, owing to the easy route proposed for the synthesis.