High resolution spectroscopy of the Vanadium oxide B⁴ [pi] -X⁴ [sigma] ⁻ (0,0) Band

• Main Author: Berno, Bob
• Language: English
• Published: 2008
• Online Access: http://hdl.handle.net/2429/1115

The B⁴Π—X⁴Σ⁻ (0,0) band of VO has been recorded at sub-Doppler resolution by intermodulated fluorescence spectroscopy. Spectral linewidths of 60 MHz were typical; which enabled the hyperfine structure due to the ⁵¹V nucleus (I = 7/2) to be resolved for most of the observed branches. The hyperfine structure of the B⁴Π state is narrow except where it is heavily perturbed by the v = 2 level of the a²Σ⁺ state. The electron configuration of the a²Σ⁺ state was determined to be (4sσ)¹(3dδ)² because of the large Fermi contact interaction which arose from an unpaired electron having primarily metal 4s atomic orbital character. The transition frequencies were fit to a model which included the rotational, fine and hyperfine structure of the B⁴Π, X⁴Σ⁻, and a²Σ⁺ states. The B⁴Π / a²Σ⁺ interaction required the inclusion of an effective higher order spin-orbit parameter as well as a new hyperfine parameter, denoted by parameter e. The new hyperfine parameter is required to describe the hyperfine interactions between ⁴Π and ²Σ⁺ states. The fit included 3211 data points and gave an r.m.s. error of 0.00038 cm⁻¹.