Reactions of laser-ablated aluminum atoms with nitrogen during condensation at 10 K. Infrared spectra and density functional calculations for AlxNy molecular species

Laser-ablated aluminum atoms react with dinitrogen on condensation at 10 K to form N-3 radicals and the subject molecules, which are identified by nit rogen isotopic substitution, further reactions on annealing, and comparison with isotopic frequencies computed by density functional theory. The major AlN3 product is identified from three fundamentals and a statistically mix ed nitrogen isotopic octet pattern. The aluminum-rich Al2N and Al3N species are major products produced on annealing to allow diffusion and further re action of trapped species. This work provides the first experimental eviden ce for molecular AlxNy species that may be involved in ceramic film growth. (C) 2000 American Institute of Physics. [S1063-777X(00)01509-7].