New RFe12−xTax compounds and their related hydrides and carbides (R=Tb to Lu, 0.5≤x≤0.7)

New RFe12 - xMx alloys as well as parent hydrides and carbides have been synthesised with M = Ta and for rare earth metal R belonging to the series Tb to Lu. The range of stability of the compounds was found rather narrow, i.e. 0.5 less than or equal to x less than or equal to 0.7 making this system very similar to that recently reported for M = Nb. The crystal cell parameters and the Curie temperature of the compounds and their parent interstitial have been measured, the latter being particularly high. (C) 1999 Elsevier Science S.A. All rights reserved.