Preparation of Multicomponent Nitrides and their Crystal Chemstry

以叠氮化钠（NaN 3）为氮源，金属钠（Na）为助熔剂，制备了多元氮化物。将金属源用NaN 3和Na密封在内壁用铌片覆盖的不锈钢管容器中。将该管置于具有氩气的电炉中并在750 ℃下加热。加热后，将管冷却至室温。用液氨洗涤Na熔剂。为此设计了一种H型电解槽。用本方法制备了Sr_3Ga_2N_4单晶。晶体尺寸小于1 mm，薄片状，黄色，透明。X-射线单晶结构分析表明，该化合物具有正交对称性（晶格参数：α = 5.9579（12），B = 10.285（2），c = 9.557（2）A，空间群Pnna）。Sr_3Ga_2N_4与Sr_3Al_2N_4和Ba_3Ga_2N_4等结构。Ga原子被四个氮原子配位并形成四面体。四面体共用两条边，形成一维链。锶原子被六个氮原子包围。在Ba-Ti-N体系中也得到了红色透明单晶，而在Sr-Ti-N体系中没有得到。在含稀土的体系中，得到的是二元氮化物的混合物，不能合成多元氮化物。

Preparation of multi-component nitrides was attempted by using sodium azide (NaN3) as anitrogen source and sodium metal (Na) as a flux. Metal sources were sealed with NaN3 and Na in a stainless-steel tube container in which the inner wall was covered with a niobium sheet. This tube was placed in an electric furnace with argon gas and heated at 750ﾟC.After the heating, the tube was cooled to room temperature. The Na flux was washed with liquid ammonia. An H-shape cell was designed for this process. By using the present method, single crystals of strontium gallium nitride, Sr_3Ga_2N_4 were prepared. The crystals were below 1 mm in size, thin platelet, yellow, and transparent. X-ray single crystal structure analysis revealed that this compound has an orthorhombic symmetry (lattice parameters : alpha= 5.9579(12) , b = 10.285(2) , c = 9.557(2) A, space group P nna). Sr_3Ga_2N_4 is isostructural with Sr_3Al_2N_4 and Ba_3Ga_2N_4. Ga atoms were coordinated by four nitrogen atoms and form tetrahedra. The tetrahedra share two edges and make a one-dimensional chain. Strontium atoms are surrounded by six nitrogen atoms. Red color transparent single crystals were also obtained in the system of Ba-Ti-N, but not in the Sr-Ti N.Mixture of binary nitrides were obtained and multi-component nitrides could not be synthesized in the systems including rare-earth elements.