Preparation of lanthanide nitrides via ammonolysis of molten [(Me[sub 3]Si)[sub 2]N][sub 3]Ln: Onset of crystallization catalyzed by LiNH[sub 2] and LiCl

A convenient precursor method for the preparation of rare-earth metal nitrides has been developed. Ammonolysis of molten [(Me[sub 3]Si)[sub 2]N][sub 3]Ln and subsequent annealing yields colored LnN[sub 1[minus]x], in contrast to black powders obtained via conventional processes. Trace impurities such as LiCl or LiN(SiMe[sub 3])[sub 2] (i.e., LiNH[sub 2] under ammonolysis conditions) lower the temperatures required to obtain crystalline LnN[sub 1[minus]x] (Fm3m, t [approximately] 200-275 [angstrom]) from [approximately] 850 to [approximately] 500C.