Emission Spectroscopy and Ab Initio Calculations for TaN

✍ Scribed by R.S. Ram; J. Liévin; P.F. Bernath

• Publisher: Elsevier Science
• Year: 2002
• Tongue: English
• Weight: 213 KB
• Volume: 215
• Category: Article
• ISSN: 0022-2852
• DOI: 10.1006/jmsp.2002.8654

✦ Synopsis

The emission spectra of TaN have been investigated in the region 3000-35 000 cm -1 using a Fourier transform spectrometer. The spectra were observed in a tantalum hollow-cathode lamp by discharging a mixture of 1.5 Torr of Ne and about 6 mTorr of N 2 . In addition to previously known bands, numerous additional bands were observed and assigned to a number of new transitions. The spectroscopic properties of the low-lying electronic states of TaN were also predicted by ab initio calculations. A 1 + state, with equilibrium constants of B e = 0.457 852 1(48) cm -1 , α e = 0.002 235 9(67) cm -1 , and R e = 1.683 099 9(88) Å, has been identified as the ground state of TaN based on our experimental observations supported by the ab initio results. The first excited state has been identified as the a 3

1 spin component at 2827 cm -1 above the ground state. To higher energies, the states become difficult to assign because of their Hund's case (c) behavior and extensive interactions between the spin components of the electronic terms.