ANALYSIS OF THE MELTING TEMPERATURES OF RTX2 (CENISI2 STRUCTURE) AND RT2X2 (CEGA2AL2 STRUCTURE) COMPOUNDS [R=LA,CE,SM,ER,TM T=FE,CO,NI X=SI,GE]

Physico-chemical analysis techniques, including X-ray phase analysis a nd differential thermal analysis were employed for the characterisatio n of compounds including their melting temperature. The melting temper ature of 23 RT3X2 compounds belonging to the CeGa2Al2 structure has be en measured. The melting temperature of 19 RTX2 compounds belonging to the CeNiSi2 structure has been measured (LaCoSi2, LaNiSi2, CeFeSi2, C eCoSi2, CeNiSi2, SmCoSi2, SmNiSi2, ErCoSi2, ErNiSi2, TmCoSi2, TmNiSi2, LaCoGe2, LaNiGe2, CeFeGe2, CeCoGe2, CeNiGe2, SmFeGe2, SmCoGe2, SmNiGe 2). It is established, that the new ternary compound SmCoSi2 belongs t he CeNiSi2 structure type (group Cmcm, a=0.4088(1) nm, b=1.6320(3) nm, c=0.4008(1) nm). (C) 1998 Elsevier Science S.A.