Laser vaporization generation of the SiB and SiAi radicals for matrix isolation electron spin resonance studies: comparison with theoretical calculations and assignment of their electronic ground states as X ??

The first experimental spectroscopic study of the SiB and SiAl diatomic radicals is reported. Electron spin resonance results indicate that both molecules have X 4? ground electronic states, in agreement with earlier theoretical calculations. The SIB and SiAl radicals were generated in neon matrices at 4 K by trapping the products produced from the pulsed laser vaporization of their alloys. Electronic structure information for these radicals is especially interesting given the utilization of silicon doped materials in semiconductor applications. The observedn uclear hyperfine interactions (A tensors) for 10B, 11B and 27A1l n these molecular radicals were compared with the results of ab initia configuration-interaction theoretical calculationswhich were conducted as part of this experimental study. The neon matrix magnetic parameters (MHz) for Si 11B are 0=800(2), gll =2.0014(8), g, =2.0005(4), A, =92.4(5), and A,, =111(2). For Si27A1 the results (MHz) are 0=9710(2), gll =1.9994(8), and gL = 1.9978(4), IAL [ =10.3(6), and [A,? [=43.5(g).