【摘要】 Nd:YAG产生的二倍频532nm激光消融金属靶表面,同时含有3%乙炔的氦载气喷向旋转的金属靶,通过等离子体反应形成中性的气相过度金属-碳链团簇分子。经过超声膨胀,由Skimmer形成准直的分子束,进入飞行时间质谱仪的电离区,被193nm的准分子激光电离。实验发现,钽奇数碳链的过渡金属钽团簇离子信号较小,而偶数碳链的团簇离子信号较大。钇碳链观察到了YCm+(m=1～4,6)、Y2Cn+(n=2,4,6)和YCnH2+(n=2～6)的离子信号。更多还原

【Abstract】 Metal-carbon clusters ion signal of the transition Tantalum and Yttrium were obtained with differential sampling system and the resonance enhanced multi-photon ionization technique. The second-harmonic output of a Nd: YAG laser is used to ablate the surface of rotating metal rod. The laser vaporization of the metal rod with helium carrier-gas contained 3% acetylene. Metal-carbon mixed clusters were formed through plasma reactions between laser-ablated metal atoms and C2H2. Cluster species underwent a supersonic expansion and formed a collimated beam with skimmer and entered into ionization region of a time-of-flight ( TOF) mass spectrometer,and then ionized by 193 nm excimer laser. The results showed that the intensities of ion signal of odd Tantalum-carbon chains were smaller,while the intensities of ion signal of even Tantalum-carbon chains were bigger. The Yttrium carbide cluster ions YC m+ ( m = 1-4) ,Y2C n+ ( n = 2,4,6) and YCnH 2+ ( n = 2 6) were also observed.更多还原