The emission spectrum of diatomic bismuth

Ali, Mohammed Keramat (1969) The emission spectrum of diatomic bismuth. Masters thesis, Memorial University of Newfoundland.

[English] PDF (Migrated (PDF/A Conversion) from original format: (application/pdf)) - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (3MB) [English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. (Original Version)

Abstract

The emission spectrum of Bi₂ was excited by irradiating bismuth vapor in a discharge tube by a high power microwave generator and photographed with a Bausch and Lomb dual grating spectrograph. Three new band systems have been observed and analyzed: (i) The near infrared system (G - B) in the region λ 8820 - 8030 Å consists of 15 bands whose frequencies are represented by the quantum expression -- ν = 11869.5 + 107.0 (v' + ½) - 0.2 (v' + ½)² - [132.3 (v" + ½) - 0.6 (v" + ½)²] . -- (ii) The system (H - B) in the region λ 7050 - 6730 Å consists of a single long v" progression. The derived vibrational constants of this system are -- ν₀₀ = 14851.6 cm⁻¹; w"ₑ = 134.0 cm⁻¹; w"ₑx"ₑ = 0.34 cm⁻¹ . -- (iii) The system (I - B) in the region λ 6570 - 6290 Å consists of over 10 bands. The frequencies of the band heads are expressed as -- ν = 15477.4 + 156.4 (v' + ½) - 6.1 (v' + ½)² - [132.4 (v" + ½) - 0.3 (v" + ½)²] . -- Since the lower state vibrational frequencies of these three systems agree closely with each other and also with the known upper state frequency of the B - X system, it is concluded that state B is the common lower state of the new systems. The upper states of the new systems are designated as G, H,and I following the notation of Herzberg (1950) and Almy (1937) for the previously known electronic states of Bi₂. -- The known B - X system of Bi₂ which was mainly studied in absorption (Almy and Sparks (1933); Nakamura and Shidei (1934)) has also been obtained in emission under the conditions mentioned above. Over 270 bands have been measured in the region λ 7980 - 4830 Å. The new emission data of this system are in general agreement with the data obtained in absorption. The following expression is derived from the analysis of the emission data: -- V = 17739.5 + 132.571 (v' + ½) - 0.3271 (v' + ½)² + 0.5240 x 10⁻³ (v' + ½)³ - 0.5324 x 10⁻⁴ (v' + ½)⁴ + 0.154 x 10⁻⁵ (v' + ½)⁵ - [173.132 (v" + ½) - 0.4156 (v" + ½)² + 0.2437 x 10⁻² (v" + ½)³ - 0.8356 x 10⁻⁴ (v" + ½)⁴ + 0.72 x 10⁻⁶ (v" + ½)⁵] -- In conclusion, a general summary of all the known electronic states of Bi₂ is given.

Actions (login required)

View Item