结合DV-Xα方法的理论计算结果,对激光蒸发方法产生的SixN团簇离子的形成和稳定性进行了细致的研究。发现上述四簇离子可能以SiN3或SiN4作为初始单元,较大的团簇离子可由某种单元与另一质谱上较稳定的复合分子组成。质谱强度变化的规律表明:若团簇离子质量是Si原子量的倍数时,呈现极大值,此时,团簇离子包含偶数个N原子。其奇偶性是由初始单元强度差异引起的。

Combined with a DV-Xa calculation, the formation and stability of SixN±y cluster ions produced by laser ablation technique were investigated.It was observed in the mass spectrum that larger cluster ions were composed of one of the basic units,SiN3or SiN,,and other stable cluster ions.The mass spectrum shows that the maxima correspond to these cluster ions whose masses are times of the atomic mass of Si. The odd-even variation related to the number of N atom is believed to be caused by the differences of intensity of the intensity of the basic units.