高氮含量锂氮团簇的生成与检测

Formation and Detection of Lithium-nitrogen Clusters with High Nitrogen Content

为发现高氮含量锂氮团簇并分析影响其形成的因素,以氮气为载气,用纳秒激光分别溅射作为底物的LiF以及LiF与ZrN、BN、AlN的混合物,并用自制的反射式飞行时间质谱研究了生成的氮团簇。结果表明,用激光溅射LiF底物,生成了锂氮簇LiN+n(n=2、4、6、8);用激光溅射LiF/ZrN、LiF/BN和LiF/AlN底物,生成了锂氮簇LiN_n^+(n=2、4、6、8、10);载气参与了锂氮团簇的形成反应,且向底物中引入固态氮源物质有助于高氮含量锂氮簇的形成;实验中发现的该系列锂氮簇都含有偶数个氮原子,且依次相差两个氮原子,其中LiN_8^+的相对丰度最高,LiN_(10)^+的含氮质量分数高达95.2%,有望从高氮含量的锂氮团簇中发现具有高能量密度的亚稳态团簇材料或其前体材料。

To find the Li-N clusters with high-nitrogen content and analyze the factors affecting their formation,N2 was used as carrier gas and nanosecond laser was used to sputter LiF and the mixture of LiF with ZrN,BN and AlN as substrate,respectively.The generated nitrogen clusters were studied by the self-made reflected time-of-flight mass spectrometry(TOF-MS).Results show that LiNn+(n=2,4,6,8)clusters were generated by laser sputtering LiF as substrate,while LiNn+(n=2,4,6,8,10)clusters were generated by laser sputtering LiF/ZrN,LiF/BN and LiF/AlN as substrate.Carrier gas participates in the formation reaction of the Li-N clusters,and introduction of solid nitrogen source into the substrate is helpful for the formation of Li-N clusters with high-nitrogen content.The series of LiNn+clusters found in the experiment all contain an even number of nitrogen atoms,which are successively different from two nitrogen atoms,among which LiN8+has the highest relative abundance and the nitrogen content of LiN10+in mass fraction is up to 95.2%.It is expected to find the metastable cluster materials or their precursor materials with high energy density from the Li-N clusters with high-nitrogen content.