Crystal structures, phase-transition, and photoluminescence of rare earth carbodiimides.

摘要: Rare earth carbodiimides with the general formula RE2(CN2)3 crystallize two modifications. A monoclinic(C2/m) modification is obtained for RE = Y, Ce−Tm and a rhombohedral (R3c) Tm−Lu. The space group R3c confirmed by single-crystal structure determination on Lu2(CN2)3 indexed powder patterns of Tm, Yb Lu. use diverse chemical syntheses conditions Tm2(CN2)3 revealed dimorphic character this compound. In addition, pressure experiments have induced phase-transition from to monoclinic. This transformation comprises an increase coordination number Tm 6 7, unit-cell volume reduction in order 20 %. photoluminescence behavior lanthanide doped Gd2(CN2)3:Ln samples presented different activators (Ln Ce, Tb) revealing broad band emission Gd2(CN2)3:Ce, quite similar that well-known YAG:Ce.